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
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.
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.