These content types that you linked are for the character generator program, which go in the RPG Maker MV\Generator folder in Windows to add these custom pieces into the character generator program.
Unfortunately, on macOS it's more difficult to get to this folder as it is inside the app package of RPG Maker MV itself.
You need to go to this location like before:
~/Library/Application Support/Steam/steamapps/common/RPG Maker MV
Then right-click (or hold ctrl and click) on the RPG Maker MV app, it has the icon of the castle with the red roof. Click on "Show Package Contents" and that will take you into the contents of RPG Maker MV.
From here, open the folders:
Contents/MacOS/Generator
That's where you'd put the pieces for the character generator files.
You should be able to recognise the Face/SV/TV/TVD/Variation folders and figure out where the files you downloaded go.
Once you've done this, open up RPG Maker MV and go to Tools -> Character Generator to start using these pieces.
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For adding resources into your specific game (no character generator used) you need to make a game project and save that somewhere; then open up that project's Folder on your disk.
You'll see these folders:
img/ is for image graphics
audio/ is for sounds and music
fonts/ is for text graphics
js/ is for code scripts
You will likely be focusing on the img folder at first (for custom graphics), so open that up and have an explore. The folders in here is where you'd put your custom images like Tilesets or Title screen backgrounds.
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For future reference; none of this is DLC. The term "DLC" is reserved for official downloadable content, not content you downloaded anywhere from the internet. Everything you find on this website is not "DLC" as it is by fans in the community, rather than the RPG Maker MV publishers.
There is official RPG Maker MV DLC available for purchase in Steam that costs money to buy, that DLC should actually automatically configure itself and won't require navigating folders (if this isn't the case, then jeez that's pretty stupid...).