Chewy I feel for you.
When I started flying I was only 20 and went through exactly what you are going through. Most of the crew I flew with were older and had different interests to me. I wanted to go out when I was away and see the city I was staying in, but none of my colleagues would go with me, preferring to stay in their rooms as they had already "been there, done that".
Every now and then I'd fly with a like-minded crew and would have an absolute ball! They were by far the highlights for me
Anyway the decision I made was to stay at the airline I was with. I never let the fact that other crew didn't want to do the things I did stop me from doing what I wanted. As a result, I met some amazing people and made great friends in the cities I went to.
Everyone will tell you how lucky you are to be with BA. You are! Make some effort and have a good time, regardless of your colleagues.
Best Wishes
SG