Instructions
Load "Pokemon SoulSilver" to the main menu, and start a new game as usual. The game begins in New Bark Town, and your character starts inside his house.
Exit your house, and go east into the next building -- Professor Elm's lab. This initiates a conversation with him, and he asks you to pick one of three new starting Pokemon. Pick one of the three Pokeballs to take your Pokemon, and exit the building.
Head west toward Route 29. A short cut-scene occurs, where Professor Elm runs out and gives you his phone number before allowing you to continue on your journey. Continue west through Route 29 -- all the way through Cherrygrove City and into Route 30.
Enter Mr. Pokemon's house -- the only building on Route 30. Inside are Professor Oak and Mr. Pokemon, engaging in conversation. At the conclusion of the conversation, Mr. Pokemon gives you an item called an Odd Egg, and Professor Oak gives you the Johto Pokedex. Walk outside for a short cut-scene, in which Professor Elm calls to inform you a Pokemon was stolen.
Return to Cherrygrove. A red-haired boy appears, initiating a battle. Select "Fight" in the battle screen, followed by one of your Pokemon's listed moves, to attack him until his Pokemon reaches zero health.
Return to Professor Elm's building in New Bark Town. Upon entering, a police officer asks you for the name of the boy you fought in Cherrygrove. Type in any name. Professor Elm takes the Odd Egg from you and lets you resume your journey.
Head west back toward Route 29. When you approach the route, your childhood friend -- Ethan, if you are a girl, and Lyra, if you are a boy -- stops you and teaches you how to capture Pokemon. After the conclusion of the tutorial, your childhood friend gives you five free Pokeballs.