If you want some really wild old storage tech, a normal VHS cassette could hold 3-5gb of data. But we didn’t have any use for that much storage at the time, and CDs were taking over by the time we did, so nobody bought the VHS storage hardware.

Consider this another vote for Ubuntu or any of its variants. They’re beginner friendly, and established enough that you’ll find plenty of resources written specifically for them. Linux Mint is another one I’d recommend for beginners, it’s designed to “just work” out of the box and be an easy transition for Windows users.

Then it’s just down to using it some. First and foremost, leave Windows installed until you’re comfortable with whatever else you end up trying. Whether you partition, or make a bootable USB drive, or even just a VM, use some kind of temporary space for practice. The terminal is a lot less intimidating when you aren’t learning in your main environment, you can go break things and see what happens.