go to professor birch and you will be able to chose from chikorita, totodile, or cyndaquil a.k.a the three johoto starter pokemon.
yes you do have to beat the game to get to giant chasm. the reason being is you dont get the national pokedex until you beat the game. the eastern part of the unova reigon has pokemon from past reigons and you cant encounter pokemon from past generations if you have the national pokedex. ditto is a past generation pokemon.
after you get the poke radar use it in the grass and if a patch sparkels it is a shiny Pokemon
Kyogre
HeartHome City
They are found in Viridian Forest, but are rare.
Put it to sleep. Then it can access the Pokemon Dream World.
The Pokemon League is in Ever Grande City, but before you can reach it you have to pass Victory Road.
I only now where to catch it okemon heartgold and soulsilver in Pokemon heartgold you get it after beating archer in Pokemon soulsilver in pewter city there is a man on a hill
you can ues a heart scale in mistralton city the house next to the pokemon center
Darkrai is indeed an actually Pokemon in the game, but can only be accessed through Action Replay or an official Nintendo Event.
Once you beat the game, the Spring Path will appear on the right side of Route 214.
The legendary Pokémon you can get in Gold are Raikou, Entei, Suicune, Lugia and Ho-Oh.