<p>Many students wear jeans with a nice shirt to an interview, polo type shirt is fine, and I am an alumni interviewer, I always say good luck , it's been very nice talking with you or some version of that. If you relax and be yourself you will be fine and ask questions, you can write them down beforehand as others suggested. It shows your interest. Good Luck! And I mean that in the truest sense. You have a lot to offer a college, but you need to believe that!</p>