@jaiden4079 Qubes is pretty advanced but a very good daily-driver OS choice if you're comfortable with getting into that sort of stuff.
As far as FF Addons go, I'd recommend uBlock Origin, Decentraleyes, and HTTPS Everywhere for sure. Also definitely a password manager if you don't already have one. Multi-Account Containers is also neat for keeping sites isolated, especially paired with the temporary containers addon that deletes all data in temp. tabs after they're closed.
@jonah would you recommend first party isolation as a replacement to multi-account containers?
@jaiden4079 not sure, I don't use uMatrix/NoScript. Presumably it'd be useful if you visited a site that required JS, so you're forced to disable NoScript but also don't necessarily want to download the JS libraries from Google/whoever's CDN.