> I'm using Unity, so creating a github repo with the root project directory would be fine, right?
Correct
> Windows Build of the Game should be uploaded to the releases page of Github repo (and linked of course in the itch.io project description), right?
The release(s) should definitely be uploaded to itch.io. No need to cut a release on the GitHub repo itself, but I think that's a good idea 馃憤馃徎
> I also see a section called Uploads on the itch.io new project page, what should I do there, upload the build there too or leave it empty (if allowed).
That's where you'll attach the game executables / downloads. This game is a good example: https://zaphyk.itch.io/neon-skylines.
> Second thing, top of the create new project page says: You don't have payment configured If you set a minimum price above 0 no one wIill be able to download your project. Is configuring payments necessary?
Nope - not necessary.
