Well, that's a good start. The book often recommended here for those interested is this one:
but a book more similar to my intro course was this:
The math used is largely differential equations. Those are usually taught after 3 semesters of calculus at university, though many students in the US take the first two semesters as "advanced placement" courses in high school.
Textbook wise, "Microelectronic Circuits" by Sedra and Smith and "The Art of Electronics" by Horowitz and Hill are the go-tos for university electronics courses. The latter has a companion lab course book, hands-on experience is essential.
Standard equipment is a breadboard, lab power supply (with adjustable current and voltage), multimeter with microamps range, function generator, and oscilloscope. Various component assortment kits can be bought to provide parts.