If you load the map and see purple walls or giant "ERROR" signs, you likely need the . Most GMod maps utilize assets from CSS. Since you are not using Steam, you must download the "CSS Content Addon" from a site like GModContent and place it in your addons folder just like the map.
Use WinRAR or 7-Zip to open the download. fnaf 1 map gmod download no steam better
GameBanana is the gold standard for GMod maps outside of Steam. "FNAF 1 Enhanced" or "FNAF 1 Remastered." If you load the map and see purple