Maybe you could briefly go through K&R, it is both readable and challenging. Then start Rust
I would pick Rust to learn over C when starting today. Rust matches today's machine beter. It is a more organized language and eco system. And most of all learning to code corect is easier when you do not run into undefined behaviour right and left.
So a modern language like Rust will expose more concepts to you and picking up C is easier afterwards, although you might not want to.