Honestly, there isnt much to do. You can visit the Battle Tower on one of the Sevii Islands, you can complete the Pokédex, you can just train a bunch, or rechallenge the Pokémon League. If you have a DS and a DS Pokémon game (fourth generation, this doesn't work with Black/White) you can migrate your Leafgreen Pokémon to that game. Like I said, there isn't much to do. CareyPrice31FTW
When you leave Pewter City after defeating Brock.
You can defeat the Pokemon League by defeating the Elite Four and the Champion in Pokemon Soul Silver.
All you have to do is just keep going back and defeating the elite four!! $FR3CK$
After defeating Blaine at Cinnibar Gym, you must return to Viridian City. The gym will now be open, and after defeating the leader, you'll get the Earthbadge.
You speed through the credits and re-open your game. Then you can continue to catch and train pokemon.
The champion is your rival.
You have to beat the original champion in the game
Gary until you beat him and then you get put into the hall of fame and you become champion
Lavender city After Defeating ghosts spirit
When you leave Pewter City after defeating Brock.
after beating eliet 4 and champion
One Island is only accessible in Pokemon Red, Blue, Green, FireRed, and LeafGreen, although it is possible to access Kanto from Johto after defeating the Elite Four and Champion at Indigo Plateau.
After defeating Brock go right of the city.
You can defeat the Pokemon League by defeating the Elite Four and the Champion in Pokemon Soul Silver.
Defeat the elite four and become Pokemon champion with 60 Pokemon recorded in your pokedex.
well it will be good to have Pokemon on you and maybe use some attacks
After becoming champion of Hoenn by defeating the pokemon league