Distro wise, I'd probably go Ubuntu simply because it's the most "mainstream ready" option. There's not much you run into that is not going to play nice with it compared to a lot of distros. It also takes a lot of pain out of the swap out of the switch at times due to that.
Honestly, the best advice I can give is to just use it as you would any other OS. It seems like common sense advice, but you really pick up a lot just by treating as if that's all you have to work with. The most important thing is to master the terminal. Once you know the basics, you're set. At this point, swapping to Linux has never been easier so you won't run into as many compatibility issues and whatnot like you would have a decade or so ago.
Explore. You're trying something new. There's no correct answer here. It's like picking a main in SSB. Tier levels don't mean shit if you hate who you're playing with. Figure out how to survive if you were left with only the terminal, and you'll be fine.
Honestly, the best advice I can give is to just use it as you would any other OS. It seems like common sense advice, but you really pick up a lot just by treating as if that's all you have to work with. The most important thing is to master the terminal. Once you know the basics, you're set. At this point, swapping to Linux has never been easier so you won't run into as many compatibility issues and whatnot like you would have a decade or so ago.
Explore. You're trying something new. There's no correct answer here. It's like picking a main in SSB. Tier levels don't mean shit if you hate who you're playing with. Figure out how to survive if you were left with only the terminal, and you'll be fine.