C is great for learning about how computers work at a low level. In my college, we started by writing a simple compiler. This should force you to understand pointers and memory which, as others have mentioned, are fundamental. You'll have to both know how the assembly works and to write correct C code. So writing a simple compiler will force you to understand it two different ways at once. My opinion is you'll learn more by diving in and doing things, especially with your existing programming background.

But, for your own sanity and everyone else's, do not start new projects in C! (Aside from purely academic ones for you to learn.) The point of a programming language is to help humans write safe and correct code. In this sense, C has completely failed. The syntax itself is just begging you to make a subtle mistake. And due to lack of memory safety, even the most well tested and scrutinized projects in C/C++ (such as Chromium) suffer from buffer overflows or memory leaks, potential security vulnerabilities that are automatically prevented by design in other languages. If you need to do something low level with any sort of confidence, use a memory-safe language like Rust, which can even do interop with existing C libraries and code.

(Edit: typo)