You arrive in the town of Wedgehurst after you make it past a wall of Wooloos in Route 1.
Go to the Pokémon Research Lab
You won't be able to get into the Pokémon Center yet, so go to the southeast part of the town and approach the Pokémon Research Lab to find Leon. There will be a cutscene. Sonia will give you the Pokédex. If you go into the X menu and open the Pokédex, it may show recommended pokémon to catch.
Check Out the Pokémon Center
Go outside and you will receive a Potion. Go east from the Pokémon Research Lab to find a Rare Candy. Go west until you can go north. To the north you will find Hop, who shows you the Pokémon Center. You can rest your pokémon there and buy supplies such as potions and healing items. You can access your Pokémon Boxes, as well. To the left of the Pokémon Boxes, you can talk to the person to change the nicknames of your pokémon or have them learn or forget moves.
In the northwest of town, next to the clothing shop, there is a Poké Doll.
Go north from town, and you will meet Hop, who tells you about the Gym Challenge. Go north from there and look for a sparkle near a rock at the top of the stairs. Check on it to get a Revive. Go east from there and continue along the path. You will eventually reach Route 2.