DeGoogle Yourself

First and easiest thing would be doing as much of your work offline as you can. Avoid uploading to Google Drive or starting documents on G-Suite, except where practically unavoidable, I'd imagine:

• Group projects
• Assignments published to Google Classroom with no alternative submission options (print, email, etc.)
• Official correspondence through school-provided Gmail

If your school district distributes Chromebooks,

• Do you have / can you afford your own laptop?
• Does your school allow personal laptops to connect to their network, or allow having one at all?
• Are there situations where use of your Chromebook is mandatory and could force you to carry two laptops?

If you have your own computer, only log in to your school account in a separate browser or browser profile. And of course, if you are in the market for a laptop, consider used and refurbished options instead of whatever pre-made e-waste they are selling brand new for $200.