I went on the Liberty of the Seas for New Years last year, such an awesome cruise and completely wild! New Years Eve was so fun, people were partying all night long, I didn't get any sleep haha....most of the other nights as well too.
There are going to be TONS of teens on your sailing, guaranteed. We had a Facebook group made after that cruise, and there were over 150 people that joined it.
You're gonna have a great time! Get ready to party haha!