Yeah, I was using someone else's code. I've made a number of 2D and 3D shaders. I prefer using the visual shaders rather than code because I like how it helps me structure my thinking and also see all the options possible. But really I had to learn how to write them in Godot's version of GLSL before I could effectively use them. I've found that converting shaders from Godot's GLSL into a Visual Shader really helps me understand how they're working.
Yeah I spent about 1.5-2 hours every night writing them. My brother said it would help me to get people interested in what I'm working on for when I'm selling my own games as opposed to working on other people's for money. I would also recommend you check out my (FREE) course on learning how to be a software developer through game development with Godot. There are only 6 classes, but I spent a 40-hour week on writing each one. I thought perhaps I could make money that way, but it turned out to be too much work so I made them free to the Godot community. Some of the code is not the way I would do things in Godot now, but it teaches a lot about the engine, as well as source control, unit testing, and a LOT on game design. There are a ton of links in there on object-oriented programming, the history of video game design and development, etc.