In some ways procedural modeling looks like programming, it’s difficult to find tutorial that will teach you how to build a complete software for obvious reasons.
Also you have tutorials that teach you the basics of a language, but only a few will teach you programming theory, or how to think like a programmer alongside.
While geo node is at the edge between programming and 3D graphics, tutorials tends to be at the edges too. Some of them will teach you clever tricks, a few of them explain the theory behind it or stuff like vector math, but it’s such a deep topic I don’t see how someone might cover everything that is has to offer in a short video …
I forget to mention this super cool thread :
Seems like a good starting point 