Where to start in machine building? both manual and CNC machines

I've recently freed up a small room with a sturdy metal table and a few second hand power tools and the main reason why I set this up is to get into machine building and metal machining.

considering I have no experience operating a CNC nor I know much about electronics, what would be a good project and/or purchase to get a feel for it so I can then progress them there?

I have a fair budget for this project, around 500$ for a proof on concept and basic tools and machines and then I can invest possibly thousands.