Comment by btilly
My apologies for having missed this request.
I don't have good suggestions for a good set theory textbook. Grad school was 30 years ago, and I didn't specialize in logic.
The best set theory book that I read was https://www.amazon.com/Naive-Theory-Undergraduate-Texts-Math.... But that one is aimed at people who want to go into math but do not wish to specialize in set theory, and not at people who want to actually learn set theory.
Thanks! I read through a bunch of that textbook when I first decided to learn more maths a few years ago, but I relatively quickly started dual-reading a different textbook ("Introduction to Set Theory" by Hrbacek and Jeck), which is a more in-depth, non-naive introduction. That's the book I'm continuing to work through now.