Cherrygrove City
From Pokémon HeartGold & SoulSilver Wiki
Walkthrough
After making it through Route 29, you will come across Cherrygrove City, a small town with the ocean to the west. Here you will find the first Pokecenter and Pokemart in the game, though not every feature is yet usable in either one.
An old man should notice you as you stroll into the city. After introducing you to elements such as the Pokecenter, he will give you a pair of Running Shoes, an item not found in the original Gold or Silver that allows you to run rather than walk. To use it, hold the B Button or press the button on the touch screen to set your character on auto-run mode.
Heal your starter and check out the town. There isn't much to be seen for now. When you're finished, it's time to take the northern path to Route 30. As you leave the city, though, the same old man who toured you through the city will approach you again, this time giving you the Map Card for your PokeGear. With this, you can open up a map and check where various locations and events are. The map also has added features that weren't in Gold or Silver.
As you leave the city, on your second time through on your way to New Bark Town, you face the red-haired boy you saw outside the laboratory, he is named Passing Boy at this point in the game. After trash-talking your Pokemon for a bit, and revealing that he is going to become the strongest trainer in the world, he will battle you. His Pokemon is the starter dominant over yours (e.g. you = Cyndaquil, he = Totodile, etc.) if he has a Chikorita it will give you 67 Exp, the other two starters he may have give you 69 Exp. When you win you will recieve 500 yen. If you're feeling unlucky, you might even want to save before you head for Route 29 just in case he does beat you. (If he does...good luck on your quest...)
Items
Pokemart -
Potion - 300 yen Antidote - 100 yen Paryzl Heal - 200 yen
