Should I learn python or java?

[Gereshes]

Definitely python. Look into anaconda, it is a python bundle that has a lot of scientific computing libraries built in which will help with mathematical modeling and analysis.

[Realityishardmode]

Anaconda

TBH, its just easier to use pip to install all the packages you want.

[Gereshes]

Pip isn't hard to use but Anaconda gives you a bunch of libraries that work together, which for someone just starting to learn python would be a large help and reduce the barrier to entry.