Any help/tips for my first job interview?

I applied at this local ice cream place and they called me for an interview today at 1:30 est. This is my first job interview so any tips? I know i walkin shake their hand and wait to be asked to have a seat. Once i sit they ask me questions right? So i always give them good answers. But kinda questions do they ask? and is there anything that i need to know during the interview? like payment and my SS# or anything? thanx