Frankly, I don't see anything interesting in that list, especially for amateurs. As an amateur compiler writer you would probably want to make something useful

Frankly, I don't see anything interesting in that list, especially for amateurs. As an amateur compiler writer you would probably want to make something useful in a few weeks, not waste a year playing around. And it's a very different story. It's essentially about making a meta DSL, that compiles into another language and plays well with existing libraries, tooling, the whole ecosystem, but also does something special and useful for you. So, you should learn parsing, possibly recursive descend for the code and something else for expressions, a bit about working with ASTs and that's pretty much it.