I self-learned lisp last year using the old SICP book, but I do consider myself a fairly expert programmer, and I felt that book was a bit hard at the end of it.

IMHO the key difference of lisp's eval wrt python's eval is that it takes in input a parsed expression (a lisp list) and not a string. In lisp though you don't have to use eval much, because the macros allow you to transform the expressions from your programs directly (take in input parsed code, return a different code structure to be executed). The quote and quasiquote functions are there to make that easy!

I don't know javascript enough, but in python you'd have to use eval and use some kind of parsing package crazyness if you wanted to implement a similar macro system!