Lisp isn't hard to learn. It can be taught poorly, and it does have some "high level" concepts, especially if you're coming from the imperative "classic" programming world.
But today, may of the modern languages have aspects very similar to what Lisp offers, so there is likely not much "new" in Lisp compared to other languages, especially Python.
My "hurdle" with Lisp (and Scheme) was simply "lambda". Essentially, my fundamental problem was I had nothing to relate to what a "lambda" was, why it was called "lambda", etc.
If it was named "function" or "routine" or something, it would have been trivial. But as is, the word "lambda" was meaningless in every way. They could have called it "mork", "bleem", or "fizbin" and it would have been as useful.
Once I grokked "lambda", the rest fell in to place.
If you're interested a A Lisp (i.e. a language which is essentially from the Lisp family), then Scheme is a good choice. But, Scheme is NOT Common Lisp (which is what "Lisp" typically means today), they are really different languages.
If you want to learn Common Lisp, I would start with Common Lisp and skip Scheme.
You can look to Practical Common Lisp to get you in to writing Lisp without "having to learn it" so to speak.