I am having trouble getting into scenario editing and modding

So every now and then I am a bit busy with the scenario editor, and before Definitive Edition was released I also made a few mods (I used advanced genie editor) for the game which introduced custom tecnologies and custom civs. I was very happy with this being possible for my childhood game.

However, the problem I'm having is that the information to make such mods is really scattered around and for Definitive Edition I'm not even sure where to begin anymore at all, and I couldn't find any proper guide to get me into it again. I tried to check the official forums to maybe get a tutorial but no luck there either.
I can still figure out with trial and error on how most of the scenario editor works, but to get into the deeper part of triggers for example, like using custom variables, is something I'd like to use but something I definitely need more explanation for to understand and use it myself.

Is there still an active group of people here who is into modding and scenario editing? Or does anyone know a good source for tutorials on how to mod the Definitive Edition of AoE2? I would really appreciate either.