When I'm with girls 1-on-1 at parties, what do I talk about ?

Parties and clubs where I am from are really easy to be with a girl 1 on 1. But when we sit down together I really don't know what to talk about, and the music is often a bit too loud so I often have to ask them to repeat themselves. Even when we get handsy, I don't know what to say to escalate situations or at least to have a decent conversation ?