Apologies to interject into your conversation.
Ganondorf does not appear in the games, making it one of the few Zelda titles to not feature him, though he does have an Easter egg related to him. If you get the game, see if you can find it.
You can call him whatever you like but by the canon he is known as Child Link, same as he was called that in OOT to differentiate him between his child form and adult form. Alternatively you could call him OOT Link.
I'm not sure what you mean but I guess you're talking about the hidden fourth morph mask. Without getting into too much because of spoilers, you need the rest of the masks in the game to get this one. As for it's use, it's kind of a late game boss breaker.
There are four temples in the game: Woodfall Temple, Snowhead Temple, Great Bay Temple and Stone Tower Temple. If you're wondering why there's not as many temples in the game, it's due to the game focusing more on sidequests and mini dungeons of which there is six. Trust me though, they're still as good as OOT dungeons/temples.
There is Clock Town, which is at the centre of the map, Woodfall Swamp, Deku Palace, Romani Ranch which are all south, Ikana Valley which is east, Snowhead Mountain and the Goron Shrine which are north, and the Great Bay which is west. In between them is the Termina Field which is around Clock Town.