Thank you brother. You've been a massive help! Seriously, know it's appreciated :)

Also you can add new land, new NPC's but best one for NPC's is immersive AI and interesting NPC, as well as for new lands and quests I'd suggest wyrmstooth, vigilant of stendarr, dawnguard, bruma, skywind etc.,

for survival frostfall, wet & cold and frostfall.

There are also retexure mods for every single thing in the game, reshade to make game look pretty, but most used are ENB injectors and ENB presets.

for horses I think I forgot this one but it was probably named immersive horses.

Then there are many NSFW mods both on nexus and loverslab but best engine for this is OSA and for loverlab, sexlab framework

If you want to install mods manually then I'd suggest installing mods like inigo, and recorder.
Animation mods you can find a moveset of any game, you can literally copy paste moveset from DMC if you want to just find a moveset mod and required animation mod tools to install it or again you can just one click install it with vortex or wabbajack

To be honest you don't have to go through all this hassle, I think there are tools available that install tons of mods for you but I can't really just name one mod, Skyrim is like an experiment ground, you can mod it however you like, you can turn it into survival, horror, anime, cartoon, comic even NSFW stuff, but best thing about Skyrim modding is it's animation mods.