Comment by Rendello
I always wanted a reason to learn C, but couldn't figure out a good project for it. I ended up learning TempleOS' HolyC as my introduction to low-level programming, funnily enough.
If you're familiar with web programming and data engineering, WebAssembly might be a good way to get into low-level programming. I've written a few web extensions in Rust, compiled down to WASM, and lots of low-level languages have WASM targets now.
The project I keep wanting to pair learning C with is an extremely simple IRC client in the terminal. It'd give me the chance to learn the language and the protocol at the same time.