Im a teacher that used to use Google to plan lessons, any advice?

I was looking at getting proton ultimate so I can use a sort of cloud service but I can't really find anything on how good their docs and slides are. I've seen libre mentioned on here but I've never heard of it? I was going to just check out both but I thought I'd ask here.

I liked that the drive let me flip between lesson plans and slides easily so if someone can suggest something that's like that I'd really appreciate it :) I'm just not the most tech savvy, but all this mess makes me appreciate that I got a xiaomi phone lol