Talk to oak after you beat the pokemon league.
No
there is no national dex in Pokemon emerald. but, you can trade it from Pokemon leafgreen, and firered.
Yes, but you must have the national pokedex
you have to mirate growlif from Pokemon firered. To get growlif in firered you need the national dex then you can catch it on route 2.
They grant access to Indigo Plateau, where the Elite Four and Pokemon Champion reside.
Access to the Pal Park Pokemon Ruby, Firered, Leafgreen, Sapphire Or Emerald
The Sevii Islands(islands 4,5,6,7)
Provided you have the national Pokedex. Yes.
If you get squitle as your starter, once you get the national dex, it will be a roaming Pokemon
you cant find it you have to migrate it from Pokemon leafgreen or Pokemon firered.
You have to trade with firered or leafgreen to get the national pokedex.
catch all of the Pokemon in the kanto region then go and see pro. oak and he will give you the National Dex