I would argue that if you’re really interested in systems programming, learning C is required just because the vast majority of the resources on systems programming is explained using C. The only notable exception is the Book Rust In Action! That being said, is your goal to be a systems programmer or a rust programmer? If it’s the latter, then learn Rust! But, as it seems that you are learning programming in general, learn the basics and data structures algorithms (these are rather language agnostic).