Write a toy compiler for a basic like language, you'll learn about what your languages are actually doing.
In fact, this summer I wrote a 3-part tutorial series on implementing a BASIC compiler: Let's make a Teeny Tiny compiler (https://web.eecs.utk.edu/~azh/blog/teenytinycompiler1.html)
My first program ran on a CHIP-8 machine (COSMAC VIP), though I didn’t realize I was targeting an interpreter and not machine code.
Great series of articles!
Parsing (should be) easy, the backend is hard but well documented and trodden, but the semantic analysis and error handling is where the real murky water is (Especially when you start trying t optimize it, like adding caching or threading or deferred execution)
You write a compiler for a Java-like language in several steps: a parser that organizes the raw code, then a compiler that emits the virtual machine code, then a translator between the virtual machine code and assembly (and then, between assembly and binary).
I've considered reworking it into a compiler, but never quite gotten around to it. Perhaps a challenge for the near year.