You can read your student code, most of them do not have anything that compels you to use the services that are provided. If that is the case, refuse to use the service and make your position known, they'll generally give you a workaround or if they say that's how it is, you can ask for the part of the student code with the nonexistent objective reason why you must use it.

If you don't want to be a squeaky wheel, there are technical ways of limiting the information loss, but the easiest is to not install anything and be conscious of what location, network, & device you use

Just use gmail through the browser instead of installing stuff like the gmail app on your phone, and you can have it forward it to your email so you don't need to open gmail to get school mail. You'll probably just need to login for replies.

And when it comes to work in the future hopefully you'll be a provided with a work device. I wouldn't use a work device for personal use even if it were running Linux, and wouldn't install work related programs on personal devices. I just consider work devices and programs to be spying on me as default.