That's commendable. The pool of questions and answers includes explanations and references below the answers for every question so you can learn the information.
If you know basic rocket design fundamentals, Cp/CG relationship, etc, you will do fine for half the questions. Unfortunately, the other half of the exam does require rather mindless memorization of impulse classes and distance tables.
All the basics on methodology and theory, from stability, drag, impulse, staging and achieving high altitude are in Stine's book, but you won't find a large proportion of the questions on the test relating to some of this "design" information.
The 2008 version of NFPA 1127 is out of date. It is revised about every 5 years and there were some significant changes.NFPA 1127: https://unh.edu/rocketcats/NFPA-1127.pdf
FAR 101.2: https://www.ecfr.gov/cgi-bin/text-idx?rgn=div5&node=14:18.104.22.168.15#sp14.2.101.c
HP Safety Code: https://www.nar.org/safety-information/high-power-rocket-safety-code/
That's all I used for my test.