Install addons, ragdolls, maps and others on Gmod Mac OSX

Hi all!
I’m Lantis and I’m new in the forum.
First of all, sorry for my bad english.

Some time ago I bought Gmod, but since I do not know where to start, I stopped using it.
I’ve taken it up again, and I still know how to use. Especially since it is difficult to find tutorials for the MacOS version of Gmod.

I got some props like a ragdoll and I read that there are tools and put them in
library / application support / steam / steamapps / common / garrysmod / garrysmod / addons

I made a mess and I think I did wrong things. at the end I deleted and reinstalled gmod but disappears the game folder in the folder called common.
You are now in the folder with the name of my own steam.

The problem is that sometimes there are downloads that come with the folder contents and material model. What do I do with these folders?

I put the downloaded content from the original folders in the game? Or leave it in addons?