Oh crap I crashed. Better reinstall the OS.

Yes.

The purpose of multi factor authentication is that it requires multiple factors, that can be:

• what you know (password)
• what you have (yubikey, phone with authenticator app, etc)
• where you are (in the office vs at home)
• what device you’re on

These are the most common examples.

Most schools track a students “publishing permission” or similar, basically a checkbox in their systems that says if a student/their parents have consented to allow pictures of the student to be published by the school. It could be that your parents did not opt out, or did opt to allow publishing pictures of you.

You should check with your parents and the school. If you’re afraid of retaliation and don’t want to check, there’s really nothing else to be done.