What should you wear to an interview for a job as a checkout girl in a supermarket?

I think slacks (like black or khaki pants) and nice button-up shirt would look nice. You could wear nice sandals (not flip-flops) or shoes, and a belt if the slacks have belt loops. I don't think you'd need to wear anything dressier than that. Make sure you don't wear anything too tight or revealing! Good luck!