Hi and welcome.
What you've pictured are some taps & a screw extractor, a couple of endmills, what looks to be part of a broach, and some super thick feeler gauges?
If you're planning on selling them to pay the rent I'm afraid you'll be disappointed but if you need to tap some holes all you'll need is a tap handle and the right size drill bits.
To answer your question though I'd have to say the best way to find out about them is to get yourself a drillpress and start making stuff, this is a great hobby and you're in the right place to learn more.
Cheers,
John