Welcome on board!!
in the great forum and Godot engine world of adventures...I'm also a beginner in GDScript, so I would advise to first the basics of Python( because GDScript is like Python language )...i would recommend this books : Python for Kids( by Jason R.Biggs) - Beginning Game Development with Python and Pygame(From Novice to Professional by Will McGigan)...great books for beginners and much more game development oriented scripts learning.
1.)Learn to making the various ways to control the character(player)- Point and Click , FPS , TopDown moving , Space ship flying....these scenes you will then use on any project (a lot of this stuff is created for example FPS module and 3th Person module)
2.)Then, shooting anything (fireballs, bullets, magic, etc) and collision detections.
3.)Then HUD...(another important thing) - counting bullets, bonuses, etc.
4.)Then some AI - pathfinding,pathfollow,etc
5.)Then UI buttons,scrollbars,etc
Godot version 3 <3 will be ground-breaking and will have Visual scripting for easier games...so won't be necessary to do much scripting but you get more freedom and control if you learn GDscript.
Good luck and joy in making games in Godot!!
