For those who might be looking for a good introductory book to Emacs, here is a book that also is really comprehensive.
Waclena, K. (2024). _Use GNU Emacs: The Plain Text Computing Environment_. University of Chicago. https://www2.lib.uchicago.edu/keith/emacs/
You can browse the book in the web, or download it in PDF, ePub and Kobo ePub.
