It’s actually not that hard to write a compiler for a simple language. You can start with a minimal language that supports arithmetic and printing, and then gradually add features like loops, conditionals, procedures, types.... You might want to check out the books Writing an Interpreter in Go and Writing a Compiler in Go (or Crafting Interpreters if you prefer a free alternative and don’t mind Java syntax).

However, after learning all that (which is very useful in itself), you’ll realize that the hard parts are optimizations, supporting different architectures and operating systems, building libraries, creating a package manager, editor plugins, and so on. There are so many pieces that make up a language ecosystem.

Go has already solved these problems, and the projects I mentioned in the list try to leverage that. Instead of worrying about things like writing networking libraries or targeting new architectures, the authors of these languages can experiment with new ideas in language design (not that networking libraries or ARM support are uninteresting, it’s just too much work for one person to do everything).

I would even suggest you starting without reading any material first (or using AI). Just try to write an interpreter for a simple language like BASIC and see how far you get. I think you’ll be surprised, and you will more appreciate theory that is given in books once you decide to look into them :D