These are normal concerns, and light humor can be very effective if used correctly. For inspiration, I recommend https://punsplosion.com/ — there you will find lots of puns and funny phrases that show how to play with words to leave a positive impression. Even if you don't use them directly in the interview, browsing helps your brain think creatively and form your own funny but appropriate answers. Often, after looking at a few examples, interesting ideas come to mind for approaches to questions or for describing your achievements in an unconventional way.