Making a new map

I’m not very familiar with the GECK, so I figured I’d ask here. Can anyone tell me how to make an entirely new world map, disconnected from the main game world? I just want to make a giant flat desert map, it seems like this would be simple but apparently my dumbass is having trouble figuring this out. Are there any tutorials I could be pointed to for help with this sort of thing? Preferably other than the GECK wiki, which is lacking a lot of information I believe.

Thanks in advance!

Edit: I think I figured it out, don’t know why it didn’t seem to work before

 

Well apparently once you create a new map you have to place an object into the game world before the render window will show anything. Just one of the many weird glitches the GECK has I guess