I am not a teenager, but I was not that long ago! (well, ten years ago). But I thought I'd give some advice here that I wish people had given me:
Study the Bible - Hard
Get accountability software onto your computer - check out
http://x3watch.com/ for one such example - this will help build accountability, espicially for young guys struggling with porn etc. Pick someone you trust to partner with in this.
Find some older Christian who you respect and ask them to mentor you! (Disciple you).
Do a study on the places in the bible where it says that something is the will of God for you - for example;
"This is the will of God, your sanctification; that you abstain from sexual immorality" 1 Thess 4:3
"Therefore do not be unwise, but understand what the will of the Lord is. And do not be drunk with wine, in which is dissipation; but be filled with the Spirit" Eph 5:17-18
" Rejoice always, pray without ceasing, in everything give thanks; for this is the will of God in Christ Jesus for you." 1 Thess 5:16-18
"And do not be conformed to this world, but be transformed by the renewing of your mind, that you may prove what is that good and acceptable and perfect will of God." Rom 12:2
"For this is the will of God, that by doing good you may put to silence the ignorance of foolish men" 1 Peter 2:15
"For it is better, if it is the will of God, to suffer for doing good than for doing evil." 1 Peter 3:17Knowing God's revealed will for you and implimenting it in your life is a good start to knowing His unrevealed will for you!
Anyway, that's all I'll put here - from a man who was once a teenager to you
Boaly