Which modmanager should I use? I've seen that Vortex can be used but the majority of people I've seen don't like it. I'd like to mod Skyrim and Darkest Dungeon
Meh, Vortex works just fine for most things. Some games require manually installing extenders or other utilities but so do the other mod managers. Plus other mod managers are often game specific whereas Vortex is one for many. I don't know, just my opinion but Vortex works fine for my use cases. Skyrim, GTA, Starfield, Cyberpunk, Baldur's Gate 3, Jedi Survivor, etc
I've seen a lot of hate regarding Vortex, often backed without any arguments. So I guess you are just supposed to hate Vortex, but to be honest it works just fine for me. Try it out yourself, if you don't like it or run into issues you can always try something else.
Depending on your browser, it should prompt you asking if you want to open the link in Vortex. You can set it to always open and then Vortex will handle all the downloads from there on.
The different mod loaders really confuse me. Do Vortex and MO2 offer pretty much the same thing? Will it show on Steam that I'm playing Skyrim/New Vegas etc. and log my hours ok (rather than saying I'm playing the mod loader)?
Follow up question: What mods should I get for Fallout NV if I were to try this out? (I've never actually finished that game)