Ask HN: Best way to learn math fundamentals?

I'd like to teach myself more math. It has always been a subject I've been interested in, but after calculus and statistics in high school, I stopped learning entirely.

I need a refresher on the basics like polynomial algebra, trigonometry, etc, before moving forward. The end goal is to have a solid understand of calculus and linear algebra, for no reason other than the joy of learning something complex and potentially diving into a little ML theory. I've used Khan Academy in the past, but have found that I learn better when I can read what I'm learning.

I'm curious what the HN community would recommend. Is there a textbook or set of textbooks that you think are better than others? An collection of online material that you think could help? Any advice is appreciated.