Here's the modding guide where you can get started in. Sort of outdated, but still works! And here's the Unity wiki when using the Open Source Baldi Project or related!
Modding Discord ListLinks to well-known and active Baldi Modding Discord servers can be found here.
- Baldi's Basics Discord Server (unofficial, owned by MissingTextureMan101)
- Baldi's Basics Modding Discord (also owned by MissingTextureMan101)
- The Cut Zone (owned by LellyLL)