How do I get past my school admin?

Alright so I just wanted to download some ad blockers for my browser on google so that I don’t have to deal with ads at home or school but my admin has blocked that and another thing while I was trying to download a game it wouldn’t let me and said I needed admin permission is there any way around this I am on a MacBook air and I just want to download undertale on to my laptop to play at home.