2D games are the best place to build your first complete game. They use sprites (flat images), tilemaps for levels, and simple movement and collision, so you can focus on how a game fits together instead of fighting complicated 3D tools.
You'll start by learning the scripting language behind your engine, then follow a full project: a 2D platformer with a player that runs and jumps, animated characters, tile-based levels, collectibles, and enemies. The lessons use Godot, a free engine that is lightweight and well suited to 2D, but the ideas (scenes, collisions, animation, and game state) carry over to any engine.
Once you've finished a 2D game, you'll be ready for 3D Game Development, where you add a third dimension, cameras, and 3D models.
Brackeys' one hour introduction to GDScript, the language you use to make things happen in Godot: variables, functions, and the building blocks you'll use in your 2D game.
A zero-to-shipped beginner project: build a complete tile-based 2D platformer in Godot 4, from creating levels all the way to exporting and uploading your finished game.