Route 208 is a scenic route with Berry patches and a few trainers. You can find wild Bibarel and Graveler here. Continue east, and you'll soon arrive in Hearthome City. Hearthome City is a large city with many attractions, including the Pokémon Contest Hall and Amity Square.
Upon entering, you'll be greeted by a woman named Fantina, the local Gym Leader. She'll tell you she's leaving for a while. You can't challenge her yet. Explore the city, heal your Pokémon, and visit the Contest Hall. You can also get a Poffin Case from the Pokémon Fan Club chairman. After exploring, head south onto Route 209.