question regarding console on your server

if you create a server from the gmod main menu are you allowed to use the console in it or is it a vac?

You won’t get banned by VAC from almost anything but custom modules. You’re safe.

Actually, VAC only bans you if it detects a cheat signature in the module. So if you have a custom module, and it doesn’t have any detected cheat signatures in there, you’re safe.