Everyone dresses casually there, but I still don’t really know what to wear. I have a lot of varsity swimmers t-shirts and athletic clothes, but I also have a lot of nice clothes too.
Dress for the job you WANT, not the job you have. Watch old Baywatch episodes to get a good idea what they wear. LOL
Wear something nice, like you might wear to a casual church service or if your parents were taking you to a play, concert or show. Be sure, however, that you are comfortable.
As far as the team clothing, leave them at home. Your resume/ application and interview will tell the boss about your qualifications. how you present yourself tells the world more about YOU.