Basic stuff...

Hello, I'm new in this community and I'm trying to figure out how does all this work.
Sincerly I just wanted to write a "story-game" much like a book-game or the once from inkle's company.
I started out with the inklewriter but there were some features missing from that I guess and I asked about it to inkle's company page.
They pointed me to the ink or inky program and I was not even able to understand the difference, then I noticed there where other things like Unity or Github and I'm even more confused now...
I really wanna learn about this stuff but I don't even know if I'm asking for help about this in the right spot right now...
Hope someone will be able to help me or to tell me where should I ask and I'm sorry for my english but I'm Italian so I hope everything will be quite understandable.