sometimes these places are very relaxed about new staff, in my last job i wasn't even given an interview i was just called up on the night they needed to replace someone and asked to start work (as a kp) xD
usually they are pretty chill but sometimes they might be uptight, try to work out which one they are and act appropriately. if you're facing customers they'll need you to be polite, smart and have some sort of personality (this is really harsh but the chefs where I last worked said "we don't hire ugly waitresses", which is not really true tbh they had a well rough one). if you're in the kitchen they'll just need you to be quiet and good at your job / obedient so try to demonstrate these qualities to the interviewer.