I’m guessing this is a school and not a university? At a university students have more clout/rights, at least on paper.
In any case, getting your own machine is the way to go. You can run whatever you want on it. You could still (cautiously) use the school network, as long as you use a VPN; basically treat the school network as a “hostile” environment. That’s assuming VPN use is not against the school rules. :)