I've been on two cruises on RCI - the first time I was 13 and went with a friend (although we did make new friends) but I went in January this year when I was 16 and made so so many amazing friends, a few of them I still speak to now 7 months later! I definitely agree in terms of going to the meet and greet on the first night - it's so awkward at first but as soon as someone introduces themselves things get moving, and I'd suggest doing the first few activities just to keep getting to know the other teens, and you'll soon figure out who you're going to hang out with for the next two weeks.
I ended up having a pretty big group of people from about 14-17, so we just hung out a lot of the time, but we did spend a lot of time in the teen club even if we weren't participating in the programs. We did do some things like trivia and obviously prom (which was so hilarious).. the activities and dances are pretty much what you make them: so if you're with fun people you'll all have a good time.
Now, with boys: I actually had two little romances hahah. It was a New Years cruise so on NYE I hooked up with one guy and we kind of "stayed together" for about a week and then we got a little bored and I got with another guy (I'm not a slut but hey..when in the ocean) who I actually liked, but obviously that didn't work out after the cruise.. haha. But it did make for a fun time and in our group, there were lots of little "couples" so it was cute.
Hope you have an amazing time!