Beyond the basic math symbols you can type holding down shift on your keyboard, I don't know math symbols, or even how to meaningfully search for them.
I came across Topological Data Analysis https://arxiv.org/abs/1609.08227 and wanted to read it, but can't figure what to search for in things like image 5 of part 2 since I can't post an image.
What would I use to learn to read that on my own?
You could try searching for introductory blog articles or videos to give you some idea of what topological data analysis is about. For instance, Matthew Wright's video on Persistent Homology could be helpful, as could David Austin's article Finding Holes in the Data.
However, if your mathematics background is that of a complete beginner then you will need to study a good part of university level mathematics (and refresh background school mathematics as needed). That is a question in its own right.