I started out with nothing but a webcam - logitech C920. Start out with what you already have. Screen capture software is free- nvidia shadowplay if you have it.
My first few videos were benchmarking trending games, and reviews of products I already had. You really have to take a look at what you have already got and make do, build it up from there.
Also if you're into tech stuff, go talk to local tech stores, they may have opened items or demo items that (if you already have a re pore with them) they may be happy for you to take away and review for a few days.
Totally depends on what sort of content you want to create, but you may have to invest in a quality mic like a blue yeti or something as your video can be a bit spotty, but your audio will 100% turn people away if it's bad.