First day at Taco Bell. What do I do?

Ok so I had an interview and I called back and I was told to go to Taco Bell on Thursday, but I have no clue what to do. I don't have a uniform or anything so I'm not sure what to wear. Do I just wear nicer clothes or try to match what the workers wear or what? I'm really worried I'll under or over dress and I don't want them to rethink their decision or something. That's what I'm most worried about. And what kind of shoes should I wear? If I need to go buy stuff that's fine because my mom offered to take me shopping. Feedback would be much appreciated. :)