As I'm always boring people by pointing out, people only play fast for one of two reasons. One is because it's easier to play fast than slow, like riding a bicycle. The momentum carries you along, and the mistakes get covered up.

The other is because it impresses people and amuses them, and I suppose that's not a bad reason to do it some of the time. But God spare us the kind of sessions where everything gets played at breakneck speed and all the subtleties are ironed out of the music. (Generally speaking, the bigger the session, the more likely that is to happen. Small is beautiful.)

So build up a few tunes that you make your own, and insist on playing at your own speed, with room for the subtleties, whether or not other people play with you on them as well. And at the same time inevitably, if you play along with other people, you'll build up scores of other tunes where you can put in your stuff with the rest of the session. It isn't either/ or, it's both/ and.