I’m sure a lot of people have their opinions about what the best introductory lisp text is. I won’t add to that list since a google search will give results from reviewers far more eloquent than I am.

What I would like to suggest is that once you basically “get” how the prefix syntax works, and how to process lists, Doug Hoyte’s Let Over Lambda (https://letoverlambda.com/textmode.cl/guest/toc) is a book that can really help you -learn- lisp, to fundamentally understand what makes lisp so powerful compared to other languages. Incredibly perspective-expanding content when I first read it, and largely references many of the “great” lisp texts that helped build the language and its community into what they are today.

uLisp itself has a lot of material to learn programming with it: http://www.ulisp.com/show?1AAO

For something like Common Lisp, which uLisp is similar to:

COMMON LISP: A Gentle Introduction to Symbolic Computation

https://www.cs.cmu.edu/~dst/LispBook/book.pdf

Practical Common Lisp

http://www.gigamonkeys.com/book/

Land of Lisp

http://landoflisp.com

ANSI Common Lisp by Paul Graham

http://www.paulgraham.com/acl.html

Depends on the dialect. I learned lisp via clojure (in before all the "clojure is not a real lisp!" haters come in, please skip that) and first book I used was Clojure for the Brave and True which is a good introduction, fun to read, practical and is available for free to read online. Highly recommended! https://www.braveclojure.com/

SICP and PAIP are great if you work through them and do all the exercises instead of just skimming

regardless of experience, i recommend the little schemer, land of lisp, realm of racket, structure and interpretation of computer programs, and the courses how to code: simple data and how to code: complex data (don't be discouraged by the apparently simple titles as they cover the book how to design programs). if common lisp is really what you want, then i have lisp by winston and horn and common lisp by touretzky and find them quite nice, although i haven't gone through them, just peeking from time to time.

Little Lisper or Little Schemer.

The Little Schemer with Racket

i like practical common lisp.