Highly recommend Clojure(Script) as a nice introduction to Lisps. It has slightly more syntax (square and squiggly brackets) to avoid having to use an army of parens to denote destructuring, binding etc.
I'd say that Racket makes for an easier introduction to Lisps, at least for people not familiar with the functional paradigm.
The reason for this is that Clojure intentionally discourages many common imperative idioms by not making any effort to support them. That forces you to learn how to do things "the Clojure way". Once you know it, you realise it makes sense and it's a better way to do thing in that context, but when you are coming from outside, it can be very hard to get things.
At least it was for me, after some 20 years of programming experience. Racket? Sure, I was able to do (simple) programs without too many problems in a matter of hours. Clojure? Lots of "huh?" moments for months until the "aha" moment when things makes complete sense.
i think common lisp has much better learning material. although it has been a while since i last looked, there isnt really anything beginner friendly for clojure
beginners would do well to look at COMMON LISP: A Gentle Introduction to Symbolic Computation. it's easy going and i think everything you learn can quite easily translate to other lisps
