You can essentially use any hardware. If you already have an old pc or laptop, you can (probably) use that. If you get a new one, the only major recommendation for usage with linux is: don’t get something with a nvidia graphics card.

And where to begin: Probably some linux distro like Linux Mint or Pop_OS. They‘re reasonably beginner friendly. But, if you have some more specific questions (or need more help finding hardware or don‘t know what a distro is), feel free to ask.