I see a lot of people below saying to chose a functional language other than Haskell. As someone who's currently learning Haskell, I'm finding it _incredibly_ interesting...but I've heard that many of the free online resources don't lay the necessary foundation for learning the more advanced concepts.

I'm 6 chapters into Haskell Programming from First Principles [0], and I highly recommend it.

[0] https://haskellbook.com/