Best way to teach yourself multivariable calculus?

I did really well in calc 1 & 2, especially with understanding the concepts. My multivariable calculus teacher this semester has a very interesting teaching style. He doesn’t use a textbook & instead throws up some problems & does them on the board. He lingers on the same subject for weeks. We can use our notes on everything, including exams. He said “open everything except cell phones.” I’m not complaining & this is cool because I’m gonna get a good grade, but I don’t know any concepts at all. I want to learn & I want to understand the material. What’s the best way or the best textbook for teaching myself? I learned calc 1 & 2 with Stewart’s Early Transcendentals book. Thanks