Ask HN: How shall I get started with theoretical physics and cosmology?

I have completed my masters in computer science. I am currently working as a software developer, but I want to start dabbling with physics with the aim to become a computer scientist aiding in physics research.

I have taken discrete mathematics in undergrad, but aside from that I think the first step is to get started with the math. What kind of math should I be looking at? Is there any website/material online that helps people like me ease into physics?

I am not much of a book person, so I'm seeking other alternative. I also don't want to take a formal course. I just want it to be a hobby that I can build upon once my knowledge grows.