About source games and Gmod

Bought Gmod a couple days ago because of the obvious steam summer sale.So basically you will need CSS for Gmod.I planned to download css from my friend's account instead because CSS obviously not worth my attention.So my point is will gmod enable to use the texture from the css?

Yes you can but don't remember how
Use your google skill

Btw wrong section. @arunforce @Boombox

You can grab the assets from the Steam Workshop.

Google garrys mod CSS. You are sure to find what you need.