I'm sorry if this is an ignorant post, but I have no clue as to how to access any UGC. I have downloaded some packs from Nexus and I get how to download from Steam Workshop, but how the hell do I get the games to see the content? What folders do I put the data in and in what form? I've downloaded Antumbra but Dragonfall is not showing anything?

Unzip the zip here (and maybe rename the unzipped folder to something that makes sense):
C:\Users\*current user*\AppData\Local\Harebrained Schemes\*game client*\ContentPacks
(AppData is as default, invisible, so you'll have to type it in or do something else)