Don't feel pressured to do anything. There's all sorts of people at night clubs. The party animals, the lurkers, the "Here to make sure this idiot doesn't get themselves killed" and so on. Personally, I'm a lurker myself. Just relax however you need to (if you need to take like a book or some shit, just do it. Who gives a fuck what anyone else thinks anyway?) and enjoy the tunes, and if you make friends then that is a bonus!