If you have or are willing to learn basic python skills, Programming Bitcoin by Jimmy Song is amazing. Literally a $4000 course in a $40 book.
That sounds great
The book, quite literally, walks you through all the high school math necessary to implenent the core cryptographic components of bitcoin. You just have to know basic python or buy a pyhton beginner book. It's the easiest, most intellectually accessible programming language on earth. I have taken Jimmy's paid course, and helped contribute code corrections to the exercises. The book contaims incredible value.