I do not agree with an approach of a book that starts with bash.
Realistically, starting with the POSIX shell, most commonly seen as Debian dash, is the best introduction. Knowing this standard (and what is not in it) will let you write highly portable scripts.
From here, moving to a text on the 1988 version of the Korn shell is a conservative approach to extended shell syntax (as ksh88 predates the POSIX shell). Korn's own first edition is not a bad place to start.
Realistically, starting with the POSIX shell, most commonly seen as Debian dash, is the best introduction. Knowing this standard (and what is not in it) will let you write highly portable scripts.
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V...
From here, moving to a text on the 1988 version of the Korn shell is a conservative approach to extended shell syntax (as ksh88 predates the POSIX shell). Korn's own first edition is not a bad place to start.
https://www.amazon.com/KornShell-Command-Programming-Languag...
The ksh88 syntax also addresses mksh directly, the Android system shell.
Taking this route to bash will be more fruitful than unlearning what these other branches of the shell do not support.