I also started off around the same age with GameMaker; if it’s even half as good still as it was in the 2000s, can definitely recommend it!
In the beginning all I did was fool around with the example games and tutorials, and that got me started well. Like taking a bouncy ball game, changing sprites, playing around with changing things in the existing logic and every now and then accidentally stumbling upon an interesting mechanic.
The drag and drop interface is really nice for starting out; eventually I got into the scripting part and found out that I had kinda learned “coding” along the way
