Not sure which title to choose while creating GA

Below the name of game there is store link. Pick the one that is correct using that as a reference.

You can't giveaway that game.

Well, it's being given away in another site, so you can't give it away.

how come you want to claim a key if you don't want to play the game?

Games that are or were free in the past cannot be given away. This is due to the CV farmers who attempt to abuse free promotions to their profit, resulting in massive spam of giveaways being posted on Steamgifts.

TL;DR: Free game = No giveaway