I started learning Godot 4 with the help of a Udemy Course "Complete Godot 4 Game Developer 2D Online Course" . I have solid Unity foundations, but I found that learning Godot at the moment is not so easy, because there are many differences between Godot 3 and Godot 4. After a while I found out, that I can learn Godot 4 very effectively by starting with a Godot 4 2D Training (for example with the course above). After some while I watched then more and more Godot 4 tutorials about 3D. This route was for me quit fast to become productive.