For those who are interested in Godot Shaders, some things to know.
1. Godot uses a custom Godot Shader Language which attempts to simplify the task of writing shaders as much as it can. There is both a text format and a visual nodes-and-wires format. For more information on writing Shaders in Godot, please see the updated Shader documentation which covers a plethora of topics: what a shader is, how they work in Godot, the assets they manifest as, how you use them in a project, as well as various examples of walking you through writing them.
2. There are many good resources for finding Godot Shaders online.
- The official `godot-demos` GitHub repository which has a 2D section that includes example sprite shaders and screen-space shaders. All links here are pointing to the 3.2 branch which, at the time of writing, is the latest "stable" branch copy of this repo (is likely similarly compatible with later 3.x releases).
- The GDQuest `godot-shaders` GitHub repository for its "Godot Shader Secrets" course (all source code is under the MIT license).
- The `https://godotshaders.com` website contains many uploaded examples of Godot Shaders from the community (and works even for people who have no understanding of git source control).
- The official Godot Asset Library (section: Shaders) website similarly has many uploaded examples of Godot Shaders from the community. These are directly downloadable straight from the Godot Editor's `AssetLib` tab on the main toolbar.
Source/Full Disclosure: I've been a (minor) Godot contributor since 2017 and have seen the growth of various resources over time.