Bumping this thread but I'm too retarded to really help you. Unjokingly try the documentation in TempleOS, I heard its good. Also suckless endorses the following:
cproc - frontend for C11 for QBE.
lacc - A simple, self-hosting C compiler.
qbe - compiler backend targeting AMD64 (Linux and OSX), ARM64, and RISC-V64.
scc - Simple C Compiler.
tcc - Tiny C Compiler git repo
https://suckless.org/rocks/Other than that, you can try asking LLMs to explain concepts and other source code to you