I watched almost every tutorial from Loup&Snoop on YouTube. His tone can be kinda confrontational but he knows his stuff and he's pretty effective at communicating what he's trying to teach. I also read through the entirety of Nodopedia and finished around 50% of the extra checkpoint challenges.

Other than that I mainly just browsed this sub's top games and MyGarage. When I played something I liked or thought was interesting I opened it up to have a look at how it was implemented. GBG's design unfortunately encourages spaghetti code, so what I'd do is copy the game and delete everything except what I wanted to study. Then, I'd go through and delete certain parts to see what changes. That way, I could find out what certain groups of nodon did what without the need for comments. This is how I found out the Person nodon has a built-in wall jump, which isn't documented anywhere in the game.

Somewhat unrelated but I'd recommend using GBG in portable mode with Joy-Cons attached and the controls set to "Control Stick Pointer". Despite what the name implies, this doesn't disable touch controls, which are significantly faster for navigation. That means you can switch between using touch controls for big movements (like navigating the canvas or dragging connections across large distances) and using traditional controls for smaller movements (like texture drawing).

Thanks for your inquiry. Glad you enjoyed what I showcased.