
Now, I will say, save machine learning/AI, calculus isn't really necessary; the world is completely discrete.
That being said, that doesn't mean that knowing calculus wouldn't _enhance_ your ability to understand and digest some of the more difficult reductions and proofs in, say, a theory of computation course.
I relied on "The Calculus Tutoring Handbook"[0]. I wanted a book that had answers to _all_ the exercises for confidence building purposes. The book goes slow and provides a great amount of detail -- the authors are pretty good at not hand-waving.
I also found \r\learnmath useful as a "I have a problem and can't ask anyone" site. They are really friendly.
[0] https://www.amazon.com/Calculus-Tutoring-Book-Carol-Ash/dp/0...
Up to high-school level:
1. Precalculus: Precalculus: A Prelude to Calculus - Axler
2. Calculus: The Calculus Tutoring Book - Ash.
College:
3. Preparation for Collegel-level maths:
3a. General prep for high level maths: How to Study as a Mathematics Major - Alcock
3b. Proof writing: How to Prove It - A Structured Approach - Velleman OR Book of Proof (2nd ed) - Hammack (it's free!)
4. Mathematical Analysis:
4a. Good prep for Analysis: How to Think About Analysis - Alcock
4b. Understanding Analysis (2nd ed) - Abbott OR Yet Another Introduction to Analysis - Bryant (has full solutions) OR The How and Why of One Variable Calculus - Sasane OR Mathematical Analysis - A Straightforward Approach (2nd ed) - Binmore (has full solutions)
5. Discrete Mathematics (a combination of set theory, combinatorics, a bit of discrete probability and graph theory): Discrete Mathematics - Chetwynd, Diggle
6. Linear Algebra: Linear Algebra - A Modern Introduction (4th ed) - Poole
7. Probability: Introduction to Probability - Blitzstein, Hwang + online course https://projects.iq.harvard.edu/stat110
8. Statistics: (for Bayesian) Statistical Rethinking - A Bayesian Course with Examples in R and Stan - McElreath + online course https://www.youtube.com/playlist?list=PLDcUM9US4XdM9_N6XUUFr...
Usually you'll be doing courses on #4, #5, and #6 simultaneously.