Job in between end of internship and full time start date?

Recently graduated and I'm starting my summer internship soon - if I get a job offer I plan on starting summer next year and want to use the time off to focus on the CPA exam. I'm not going to be doing grad school since I already have 150 cr. -- what are some good in between part time jobs to fill in the gap? I was thinking about just being a cashier or something. When I apply for these would I even mention the internship experience and my full time offer? I don't want to seem overqualified or scare them away since I don't plan working with them for long. Thanks!