After defeating Red at Mt. Silver, Steven Stone will be at the Silph. Co and he will give you one there.
You cannot get a Sinnoh Starter. You can only have a Kanto, Johto, and Hoenn starter.
No you do not need to catch Kyogre. You can get a Hoenn starter from a guy named Steven in Kanto.
Silph.Co(Kanto, postgame)
nothing search for latios/latias
In Pokemon Heartgold and Soulsilver you can get a Johto starter from Professor Elm, a Hoenn starter from Steven, and a Kanto starter from Professor Oak
you catch the hoenn legnds kygore groudon and rayqaza
Hoenn is not in heartgold version, only johto and kanto are in heartgold, hoenn is in emerald
In Pokemon Emerald, when you complete the Hoenn Pokedex, Proffesor Birch gives you a Johto starter. In Pokemon HeartGold and SoulSilver, after defeating Red, Professor Oak will give you a Kanto Starter and Steven will give you a Hoenn Starter.
You can't get to the Hoenn region in HeartGold or SoulSilver. However, Latias can be caught in HeartGold, which is a legendary from Hoenn.
once you defeat red in mt. silver he will give you a kanto starter.... After that you should go to saffron city in the silph co building and he will give a hoenn starter on the colour stone you choose.
Outside of migration from Hoenn itself, Steven Stone gives out a Hoenn starter in Pokémon HeartGold and SoulSilver. In order to receive it, you have to beat PKMN Trainer Red at Mt. Silver.
First, go to Professor Oak to obtain your Kanto Starter. Then, go to Silph Co. to obtain your Hoenn Starter from Steven, the Hoenn Champion. Go to Mr. Pokemon's to get the Blue Orb to catch Kyogre.