club dancing is basically doing whatever you feel like to the beat. This is a lot easier if you have a repertoire of moves from other styles of dance or activity that you can instantiate. Also what Villiam_Bur said.

I don't have much experience with club dancing, but at the few occasions, I was there with a girl who I previously danced ballroom-style with, and we mostly danced jive or quickstep or cha-cha, just with shorter steps to take less space and not move across the room. We had fun, and the feedback from other people was positive. But even with the club-type dancing, somehow it got much easier for me once I became good at ballroom dances. Maybe I got more confident, maybe I learned to follow the rhythm, maybe I started to understand some movement patterns; probably all of that together.