[butternoodle]

My recommendation is to use Portacle as your IDE and run through Practical Common Lisp by Peter Seibel over the course of a few days. Both are available for free online and very easy to get set up with. Practical Common Lisp provides a good foundation level of knowledge, which you can continue to use as a frame of reference for the other Lisp dialects and features as they come up (e.g., Lisp-1 vs Lisp-2, hygienic vs unhygienic macros). Once you have the fundamentals of Common Lisp down, I'd say you can then follow your interest and choose an appropriate Lisp dialect for the type of project you want to create.