For those interested in programming and game development, this channel has videos on creating a game from scratch using Java. There are many similarities with GML; even if you are not interested in programming with Java, you can learn a lot of things useful in GM too.

This video (and channel) deals with making a simple Platform game using the game maker language. You can see how the D&D actions of GM are translated into code, and how much you can manipulate them to do what you want, instead of being limited by the D&D's format. For someone with no previous experience with GM or coding, these videos can be very useful as an intro to what you can do with the software.