This download looks like an addon. You need to extract the downloaded zip and put the addon folder in your Garry's Mod addons folder. You should end up with a directory structure similar to below:
Don't know where the Garry's Mod folder is or how to extract zip files? See more useful installation tips.
santy, 344113, ElChamoSinJuegos TwT, radik_melnikov, Tio_das_paçoca, zennat.3195, Freddy Kabusu, cassiokid10, cassiokid10