Mathematical notation is not anything magical and mostly there to allow for easy discussion. Also equations are only a small part of notation and words and defi

Mathematical notation is not anything magical and mostly there to allow for easy discussion. Also equations are only a small part of notation and words and definitions are much more important, e.g. "isomorphism". Since mathematics is abstract anything used necessarily has be precisely defined. Thus, the best way to learn mathematical notation is to get some beginner level rigorous mathematics book for mathematicians, e.g. Rudin's real analysis or Lang's Linear Algebra, and read through chapter 0 and 1. Books like these tend to start entirely from scratch: What is a number? What does '+' mean? What is a sum symbol? While each field tends to have some further notation, that is often explained within the paper or in standard references and you should be able to read mostly everything after reading up on basic notation sections in analysis, linear algebra and maybe category theory.