Aquacorde Town is a town north of Vaniville Town. Here, Tierno lets you choose your starter Pokémon. Shauna will pick one whose type is weak to yours and your rival will choose the one whose type is strong against yours. Trevor will give you the Pokédex. Tierno also gives you a letter from Professor Sycamore to your mother.
In Aquacorde Town, there are two shops, one which sells Poké Balls and another which sells potions. There is no Pokémon Center, however there is a building beside the potion shop in which your Pokémon can rest.