You will need a basic understanding on how to create Doom levels to be able to do this, there are plenty of great resources online for creating Doom 2 maps.
Making custom maps in Total Chaos is easy to setup.
We use GZDoom Builder to create our maps. You can download it here.
Once you have set it up, follow these steps to start making your first map!
Configure GZDoom Builder
Once you open GZDoom Builder go to Tools > Game Configurations.
Go to GZDoom: Doom 2 (UDMF) and click it. You are going to want to add totalchaos.pk3 from your gamedata directory here. You can add this via the Add Resource button.
Click OK. GZDoom Builder should now be configured to start creating Total Chaos maps. From here, go to File > New Map. Select GZDoom: Doom 2 (UDMF) from the Game Configuration dropdown and enter MAP01 for your level name. Then click OK.
You can now start making your map. Drop a few linedefs in and a Player Start thing.
Packaging as a PK3
Once you have created your map, you want to package it into a PK3 so Total Chaos can run it. To do this, simply zip up the map wad you have created and rename it from .zip to .pk3. From here, drag and drop it into the gamedata/mods folder. You can now switch it on from the Total Chaos Launcher.
Useful ACS Commands
This teleports the player to another map spot and plays a door open/close sound effect.
(more to come)