What can a teen do on a cruise?

i have been on 2 carnival cruises. not dream, but smaller ones. age groups are usually 0-10, 11-14, 15-19. that's for carnival. i dont know about RCI. probably around the same. as far as gender goes, mostly equal...sometimes a few more females. just dont be to shy and you will be fine. there is usually a introducing night. Have Fun!!! =)