Find a textbook or problem workbook and give yourself a regular assignment of 10 "easy problems" that just involve applying the formula, 5 medium-ish problems where the solution is not so straightforward, and 2 very hard problems that test your knowledge of each chapter, such as proofs. Vary the numbers as you see fit for sections as a whole, but try to keep a consistent challenge in your homework. Having a teacher can be helpful to explain some of the nuances of math, but isn't always necessary. I know plenty of students who skip out on class entirely and study directly out of a book. Just make sure you find decent textbooks for what you want to learn. (Unfortunately I have learned out of many terrible textbooks, which I cannot, in good conscience, recommend) If you finish those three subjects up (Students take more than a year sometimes, so don't rush yourself), then check out the undergraduate math curriculum available at a respectable university and grab a book or two on the subjects that look interesting. Knowing which fields of math that are relevant to your own work can also allow you to maintain your interest and have a practical application to the knowledge you've learned. Pretty much everyone can benefit from the ideas of linear algebra and differential equations, but multi-variable calculus tends to be geared more towards physicists, while discrete math shares more with the problems studied by computer scientists.