Hi rbissessar, welcome to Cruise Reviews
I agree with f-mattox that they probably lean towards the "older" crowd, but that's not to say there isn't plenty to do on board. We began cruising with Princess in our 40s and they're still our favorite line. However, the Caribbean crowd on Princess is normally a younger crowd, 20s-60s, if it's not a long itinerary. They do have salsa dance lessons and they do have dance clubs on board. I don't think you'd be disappointed in Princess at all, but they don't have the rock wall or the ice skating rink. They do have fresh water pools, hairy legs, newly wed game, etc. The Caribbean Princess has the Sanctuary and the International Cafe. The ships are immaculate, the service is wonderful, and the food (in my opinion) is fantastic. They do have My Time Dining, so you don't have to eat at a set time. I know I've left the casino in the early morning and there are still plenty of people out and about.
I think the only way to really find out if you like it or not, is to try it. I enjoy trying different lines. I've still got quite a few to go, but have been on HAL, RCCL, NCL, CCL, Celebrity, Costa and Princess. Princess is my favorite, so far, but that's just me. Costa is next. Two totally different experiences. I've never had a bad cruise, just some better than others