Maths is a vast subject and no single book is going to help you.
But you can make a start by thinking logically and carefully. Maths is taught in schools very progressively. The important thing is not to proceed to the next step without fully understanding all previous steps so thoroughly that they become second nature. There are many websites (e.g., Khan Academy) that allow you to progress from whatever level you are at to a more advanced level. Maths is more a way of thinking—reasoning from first principles—rather than learning formulas and applying methods parrot fashion without really understanding what’s going on underneath. All great mathematicians were great thinkers. Newton, Einstein, etc., practised thought experiments and asked themselves questions to probe beneath observation. This led them to convert their thoughts and conclusions into mathematical statements. So we ended up with concepts like calculus, simple equations that expressed what would turn out to be profoundly world shattering.
It’s important at every step to solve problems to prove that you do have a grasp of what you’re learning before trying to move on. You can use the Math Homework Answers website to find questions and see the answers to questions of all grades and levels of difficulty, and you can try to answer questions yourself. Some only require a basic knowledge of maths, but demand careful, logical thinking to get to a solution.
Good luck with your quest! Keep safe!