Is it still relevant to learn C or C++ for systems or I should learn Rust

C++ is painful, obsolete, "all over the place", and arguably a historic relic from the past, and destined to end up "the way of COBOL". This of course is my personal opinion, and due to barely having touched "the dinosaur" for 15+ years, I guess my opinion doesn't really matter. As to Rust, I wouldn't know - I suspect it's a much better approach to the problem than C++ ... :/

If you want to learn a practical language, I would recommend C#. Go is too immature still, with way too many missing libraries, and an eco system far too small to be "practical" for solving solutions ending up in getting you an actual job. If you're interested in a "perfect programming language", Lisp is still unmatched, even after 60+ years of "innovation". If you want a super productive programming language, allowing you to solve in 5 minutes what needs weeks of debugging solving with other languages, my own personal baby Hyperlambda is of course the by far fastest - And it lends itself to DSL concepts through C#, allowing you to combine the two ...

If all you want to achieve though is to "land you a job", the "worst programming language on the planet" (JavaScript) unfortunately is still the winner ... :/

BTW, C is faaaaaaaaar superior to C++, simply for no other reasons than what it does not have (OOP that is of course ...)