A lot of advice columns and wasted breath is spent telling kids what they shouldn't write about. Hopefully, you already understand that there are no wrong topics, as long as you are writing about YOU. Keep your strengths and personality tight in the cross-hairs, and you can't miss.
But are there wrong topics? Should you stay away from a trip, a school play, a team, the divorce, an illness? Not if you can write about these topics and show something meaningful about yourself in the process.
One wrong topic, for sure, is "what they want to hear." What do admission counselors want to hear? Just a little bit of vivid info about you. Praise of the excellence of their world-class institution: no thanks. Encomiums to the faculty based on your occasional attendance at football games with your alumni parents: not so much. Your plans to cure cancer while toiling in their labs: I think not. Just "tell us about yourself." That's quite enough.