This is a loose list of modding sites
I cannot vouch for each and every one
They are listed here so we can easily find them
AFK Mods https://www.afkmods.com/
Bethesda.Net https://bethesda.net/
CurseForge https://www.curseforge.com
Moddingham https://www.moddingham.com
Mods In Exile https://discourse.modsinexile.com/
Nexus Mods https://www.nexusmods.com
Steam Skyrim Workshop https://steamcommunity.com/app/72850/workshop/
TES Alliance http://tesalliance.org/forums/index.php
Wolflore http://www.wolflore.net/index.php
The following contain adult content and/or nudity. Enter at your own risk.
ModGames https://modgames.net (Russian site. I have not explored this one.)
LoversLab www.loverslab.com (Much adult content)
Sun Jeong Mods and Ports https://www.sunkeumjeong.com (Nudity, skimpy)