I need help getting started with the painter function in the editor

Hello,

I need some help with texturing my maps. First of all i have to say that i already watched a bunch of YouTube tutorials and already searched in Google for answers, but i can't find anything helpful to my problem.
Well, i wanted to make a new map and most of the maps needs terraintexture. So i watched some tutorial videos, but the shown parts about the terrain painter was not acessable in my case. They have shown me the "New Material" function and already had the "grass" and "stone" and "[...]" brush there. I can't find anything like this. They also shown how to include other textures in the editor, but also here the needed "example.dds" was not there in any level folder (except for plants and other stuff). They also shown that they took these brushes from the "terrain" folder that isn't even included in this case, just the shapes folder and nothing else. So i need help (with an instruction) how do i get the terrain texture stuff. I can't find it anywhere in my folders of BeamNG (...\documents\BeamNG.drive\...).
Well... I'm not the best in explaining but i hope you could understand my problem and help me. I have absoloutly no clue about it...

- And sorry if my english is wrong at some places or a mistake there.

Thanks for reading or/and answering.