You can't.
roar
By defeating Jafar.
Generally Agrabah.
Probably Agrabah
They are in Agrabah and Neverland (Clocktower)
The original 3 and Aladin
Agrabah
Agrabah from fire type heartless
you need to lock the keyhole in Agrabah, by beating Jafar.
The same time as Agrabah after Port Royal.
You unlock Agrabah after you finish Wonderland and the Deep Jungle to get the navigation gummies. After you get the navigation gummies you go talk to Cid and he'll install them for you.