Hi Julian,

I'm cutting and pasting a response from above: I would begin with Scheme/Racket. As far as books go, The Little Schemer followed by The Seasoned Schemer by Friedman and Felleisen are great beginning books. Additionally, the Racket team has put out a free e-book called "How to Design Programs", which is another great introductory text. https://racket-lang.org also has tutorials and such-like.

Wish you all the best in your journey.