Help With Compiling For Gmod

So I am learning how to compile models in gmod. I have everything set up with the files and such, but when I try to open GUIStudioMDL I have no gmod section. I cant find an updated tutorial on how to do this. Can someone please help?

Garry’s Mod does not have the required files to compile into it directly.
Also, I highly suggest switching from GUIStudioMDL to Crowbar, which will take care of a ton of things for you instead of having some sort of problem and GUIStudioMDL not exactly helping you out.

To compile a model for use in Garry’s Mod, you would need to have either Counter-Strike: Source, Half-Life 2 (and/or any of it’s episodes), or have Source SDK installed.

Having the games is simple, but I’d say having Source SK installed is better simply because you can compile for a range of games with different commands and such. For Source SDK, I have these exact versions downloaded from the “Tools” section of your Steam game library, just to be sure everything will be working:
Source SDK
Source SDK Base 2006
Source SDK Base 2007
Source SDK 2013 Singleplayer
Source SDK 2013 Multiplayer

If you switch over to Crowbar, they have a guide on compiling models and setting up Crowbar correctly, too.

Good luck!