C is a bit dated and Lisp too wishy-washy, I'd suggest either Rust or Go for the Turing machine paradigm, and for the Lambda Calculus paradigm Haskell (or any truly comparably powerful robust "strictly" pure-and-lazy functional language --- can't think of any).

This way by covering the extreme ends of the spectrum from (A) gratifyingly roll-up-your-sleeves-and-get-your-hands-dirty petal-to-the-medal (heh) systems programming to (Z)abstractions-all-the-way-up-and-down-and-sideways algebraic-typed purely-functional glory.

With current-day concurrency approaches, easy-networked-ness etc thrown in natively in any of the above.

Once proficient in these "spectrum extremes", anything in between should be relatively easier to get up to speed with