Pokémon Gold and Silver/Violet City

Go to the Pokémon school(to the north of the Pokémon Center), it has good help for the game then if you have a Bellsprout, go to the house left of the Pokémon Center to trade it for an Onix, it will help beat Falkner, now go to Sprout Tower, It will help train your Pokémon to beat Falkner.