After Bianca teaches you how to catch pokémon in Route 19, you caught some of your own. Later you met Alder, who wants to help you train your pokémon. You go east to follow him into Floccesy Town.
Heal Up and Explore Town
To the east, you will find Alder, who will say that you should heal up your pokémon in the Pokémon Center. Then he will go to his house.
Heal up your pokémon. You can explore the town if you want. There is an old man in the house east of the Pokémon center who will give you a potion.
Go north to find Alder. He will want to start training, but he notices that you have two Town Maps and tells you to go to Route 20 to look for Hugh.