You ask a good question.
I'm not young, nor Catholic, but you also asked for input from anyone, so here's my take on it:
What the Bible says about confession
There are a couple of passages which discuss recounting our sins to other believers.
Most of the passages use a word that gets translated, in English, "confess": the greek verb is ἐξομολογέω (exomologeō, Strong's G1843).
Exomologeō comes from ἐκ (ek, G1537) meaning "out" or "out of" or "away from" and ὁμολογέω (homologeō, G3670), "to agree", "say the same thing as", "concede", "profess", or even "celebrate". In ὁμολογέω (homologeō), we have a compound of the base of ὁμοῦ (homou, G3674), an adverb meaning "the same" or "in the same way" and λόγος (logos, G3056), "word" from from λέγω (legō, G3004) "to speak". It's easy to see how a verb formed from legō or logos (speak, word) and homou (same), would mostly mean agree with, concede, or say the same as. Anyhow, the primary sense of exomologeō seems to be to speak out, or concede, the things on your heart or your conscience, in a spirit of conceding your faults, or agreeing with God. Exomologeō is translated "confess" 8 times, and "thank" twice, and "promise" once in the AV (KJV) translation of the New Testament.
We are speaking out our sins (or our praises to God) and agreeing with Him about them.
The Biblical Passages
At Matt. 3:6 and Mark 1:5 we are told that in response to John the Baptizer's preaching, people repented (John preached a baptism of repentance, for the forgiveness, or remission -- sending away -- of sins, the Gospels tell us), "and were baptized by John" in the Jordan river "confessing their sins".
As the apostles taught, we're told in Acts 19, that after a miraculous deliverance (casting out an evil spirit) many of the onlookers were awed, and as this became known "the name of the Lord Jesus was magnified" (19:17) As a result (19:18) "And many that believed came, and confessed, and acknowledge things they had done." They came and confessed their sins.
And James 5:16 says "Confess your faults to one another, and pray for one another, so that you may be healed . The prayers of a righteous man are powerful, and are very effective." In context he then goes on to consider the prayers of Elijah, which accomplished great miracles, specifically in bringing the land to repentance through causing a drought and then stopping the drought which had done so. The sense, then, is that James is telling us that through confession, perhaps to the churches ministers, and through prayers by these godly friends, God does much to put away our sins and heal us.
The word "confess" -- or what people do in going to the apostles and their successors, to the elders of the church, and so on -- is not explicitly mentioned in Christ's mandate to the apostles in John 20:23 (or 20:19-23) but it is implied. The apostles great the risen Lord Jesus, and he endows them with the Holy Spirit, and commissions them to be His successors, to do as He has done.
On the evening of that day, the first day of the week, the doors being shut where the disciples were, for fear of the Jewish authorities, Jesus came and stood among them and said to them, "Peace be with you." When he had said this, he showed them his hands and his side. Then the disciples were glad when they saw the Lord. Jesus said to them again, "Peace be with you. As the Father has sent me, even so I send you." And when he had said this, he breathed on them, and said to them, "Receive the Holy Spirit. If you forgive the sins of any, they are forgiven; if you retain the sins of any, they are retained."
As 21st century Americans we live in a time and place which is very anti-authority. The idea of authorities in the church, though, is fully accepted in the New Testament.
The Biblical Principles involved,
and some contemporary experience
There are, in my opinion, two central principles that are being exposited in these texts.
A first principle is that it is often helpful and important for us to be able to acknowledge our sins, to another human being as well as to God.
Of course, we start out by knowing that it is God alone who can forgive sins. But God can help us understand and receive the power of his forgiveness through the encouragement, acceptance, and honest words of human beings.
It's for this reason that lots of people -- lots of Christian high-school or college students, for instance -- have friends with whom they are "accountability partners". Sometimes this is one on one, sometimes in a close group of friends. They talk with their accountability partners, or small groups, about their struggles. (For instance, lots of young people have struggles with lust.) Such conversations, in my experience, have various aspects: people ask one another about how things are going, encourage one another in regular prayer and bible reading, and, definitely, report if they have messed up. What then happens? In my experience, people encourage the person who has goofed, reassuring him (or her) of God's love, but also encouraging him (or her) to stay on a good path. This kind of thing is very helpful to people (including me) in my experience.
A similar principle is invovled in 12-step organizations, like AA -- alcholics anonymous.
But in lots of cases its hard to find a good accountability partner, let alone group, with whom one has enough trust to know that the other will be completely discrete (not spill the beans), have a wide enough experience to take things in stride, and wise in giving counsel. For me, it's been great when I've had a friend whom I can speak absolutely frankly with about things in me that appall me. The knowledge that my friend sees all that ugly crap, and still sees me, as God does, in love and hope (and respect) is so very powerful in helping me walk right, and be free from the burdens of my faults. But it's been relatively rare that I have such a friend -- peer friend -- around on a regular basis. However, there have been friends I can't be quite as open with, but who still I can be pretty open with, and pray with about my faults and lacks. Again, it's strengthening. Often (not always) such relationships are mutual. My friend and I may struggle with some of the same issues, and that too gives me hope, helps me overcome my shattered confidence when I goof, and generally communicates God's grace and love through the honest Christian fellowship we have. Also, in these friendships, sometimes (actually, fairly often) my friend or friends will challenge me: see some different things I need to do, or problems in my attitudes I'm not aware of, and so on. That's both helpful and encouraging, too. And of course we pray together about all these things, which is great.
So one principle we have here is the importance of partnership, and of open discussion with a trusted Christian friend of our weaknesses and sins (as well of our aspirations). "Confess your sins to one another" can include peer accountability relationships. And not just for young folks. My senior pastor (priest, rector) has a group of clergy whom he's met with for about 25 years (the membership changes a bit as new folks come in, and some move too far away, or in time die) in which they practice, as a group, complete honesty, in complete confidentiality, about their lives, including their faults, sins, and problems. Again, it's vital in keeping them on track, and balanced, and out of falling into trouble, and whole and healed before God.
But a second principle here seems to be that of going to elders, apostolic authority, and confessing sins.
People confessed their sins, at the Jordon, not just "to one another" but to those whom God had commissioned, John, and his disciples. (When it says confessed their sins to John it must be including close followers, disciples whom he'd commissioned, because he alone personally couldn't have met with each of the people in the crowds.) In Acts, the many people who are convicted come to the apostles (and their deputies) and acknowledge their sins. James, in speaking of confessing sins "to one another" completes the verse by speaking of the particularly effective prayer of a person whose prayers have power because of their righteousness, and then goes on to talk about the prophet Elijah. Thus James is directing our attention, through examples, I think, not just to confession in the family, to a spouse or close friend or peer, but to the people God gives us as pastors, teachers, religious authorities. A lot of young people want to get counsel from an older Christian. A lot of students who are wrestling with things, including pretty hefty things, come to trusted teachers or older Christians to talk them over. And likewise come to talk lesser struggles over.
There is a special role, though, which pastors have, and which the appointed authorities in the Church which Christ instsituted have. In John 20, Jesus gives the Holy Spirit to the apostles and also gives them authority to forgive sins. He says he's sending them as the Father sent him. Jesus forgave the sins of particular persons at many points in the gospel; and now, He says, He's giving them power to forgive sins, or to refuse to forgive (where they see that repentance is incomplete, I assume). There is a measure of authority which they, as the appointed shepherds, are being given by Christ, the chief shepherd.
Thus, even when I have great peer accountability friendships available, I also go to confession. I confess to my priest -- I'm an Anglican, not a Roman Catholic -- and receive from him council, direction, and absolution. I love it. It's very difficult at times, going back, for instance, with the same stupid sin time after time, and not having made much progress on it, or even doing worse. (I usually go to the same guy when I go to confess, and he knows me well.) He prays for me. He says incredible things. I can feel his concern and love for me, and it gives me courage to go on seeking to follow God's ways and not give up. He comes up with scripture for me to think about. He gives me perspective. Sometimes what he says (the Scripture verses he directs me towards) seem sensible. Sometimes they seem out of the blue, but totally right. Sometimes he comes up with Scripture verses which seem out of the blue, and I don't get it. But, as I work with those verses afterward, I get the point and see that this really was a great word for me. This whole process helps me walk closer with God in so many ways.
God alone is the one who forgives our sins. All forgiveness of sins comes from God
Absolution -- the positive declaration of forgiveness -- is also important for me. Christ made the church His body, and commissioned the apostles and their successors, giving them the Holy Spirit, and (IMO) authority, just as John 20:23 says. Of course, it is God -- God only -- who forgives. I've never imagined otherwise; no one I know thinks or has ever thought differently. But God works through human beings. He sent Christ in the flesh, and constituted a flesh and blood church as Christ's body, to carry on His work. That, however, is a controversial point, about which different Christians may reasonably differ.
There's nothing -- NOTHING -- we have or can have, no good we receive that we don't receive from God. He, and He alone is the giver of every good gift (as James also notes). Our food each day, our health, our learning, our freedom from wars, our friends, our families -- all are God's good gifts. (My family is God's amazing and wonderful good gift even though, oddly enough, the people in my family, just like me, are imperfect, and sometimes very imperfect!) And thus of course, when a friend prays for me, and the prayer is answered, it's by God's grace that the prayer took place, as well as the answer. When a friend helps me by giving me a lift when my car's broken, God is helping me. And when a friend, or pastor -- or my priest -- preaches to me, or encourages me, or prays for me, that person is acting, effectively, often strongly, but it is God who ultimately is at work. Paul says "work out your salvation with fear and trembling, for it is God who is at work in you, both to will and to work acccording to what He, in His goodness, considers best."
And so too, I believe Scripture when it says that Christ gave power to the apostles, and their successors, and their successors, and to my parish priest, to hear my confession, and counsel me, and pray for me, and act as God's agent in effectively working forgiveness and remission (sending away) of my sins in me. But as i say, there are differing points of view on these things.
Others will differ, but I myself see no contradiction with Scripture in the Sacrament of Reconciliation, but rather exactly what Scripture says. I see no contradiction to the uniqueness of God's authority and power, but rather the confirmation of that power -- God's power alone -- working (as God has generally chosen to work) through human beings in His church, as well as directly.
And of course (a lesser matter) it also makes sense with, and lines up with, my experience, and the experience of others.
Confession, including the Sacrament of Reconcilaition, but not limited to that, in my experience, combines forgiveness, growth in our relationship with God, and healing, and power to be better. But of course, God works with us patiently, and my understanding of God's love and patience also grows as my human friends -- peer friends and also priests -- also are patient with me, as I often continue to struggle and mess up in a variety of ways. It's encouraging and helpful.
A senior member of this board, Slug1, has an awesome testimony about how God healed him from sexual brokenness (fantasy lust and masturbation) as God directed him to go to his pastor (a baptist pastor, I think, filled with the Holy Spirit) and confess fully to that guy Slug's struggles and faults. That testimony is posted on the board.