After you visit the Contest Hall, then go south and battle your friend, you can move on to Route 209.
Catch Pokémon
In the grass, you can catch Bibarel, Bonsly (Shining Pearl only), Chansey, Gastly (only at night), Mime Jr. (Brilliant Diamond only), Staravia, Starly, and (only at night) Zubat. In the water, you can catch Magikarp with the Old Rod, and Goldeen and Magikarp with the Good Rod.
Explore the Route
To the east of the Hearthome City exit, you can battle Pokémon Breeder Albert, who has a level 16 Bonsly, a level 17 Pichu, and a level 15 Budew. You get 1088 Pokédollars for winning.
Northwest of there, you can talk to the Battle Girl, and if you have participated in a Super Contest Show, you will get three Electricity Stickers B.
East of there, you will find a jar of Honey.
Go south and talk to the fisherman at the pier to get the Good Rod. You will still keep the Old Rod, so be sure to register the Good Rod if you want to use it by pressing + or -.
In the water in this area, you can catch Goldeen and Magikarp with the Good Rod.
To the north, you can battle the trainer who is running back and forth across the bridge. Jogger Richard has a level 19 Luxio. You get 836 Pokédollars for winning.
To the north, you can talk to the Aroma Lady, and if you have talked to the Fan Club owner in Hearthome City, you will get 3 Flora Stickers E.
To the west, there are berry trees.
Go back the way you came until you can go east. You will battle Twins Emma and Lil. They have a level 19 Mime Jr. and a level 19 Bonsly. You get 1672 Pokédollars for winning.
There is a hidden Revive northeast of the twins.
East of the twins, you can battle Poké Kid Danielle, who has a level 19 Pikachu. You get 380 Pokédollars for winning.
Go south across the bridge, then east along the narrow path. At the end of the path, you find an X Accuracy.
Go back the way you came and go north, then east across the northern bridge. You can battle Jogger Raul, who has a level 19 Staravia. You get 836 Pokédollars for winning.
North of the bridge, you can battle Pokémon Breeder Jennifer, who has a level 16 Mime Jr., a level 15 Budew, and a level 17 Cleffa. You get 1088 Pokédollars for winning.
To the east, there is a stone structure. If you got the Odd Keystone in Route 208, you can check on the stone structure to restore Hallowed Tower.
Near the Pokémon Breeder, there is a Honey tree.
Go north down the stairs and check on the ground to find a hidden Tiny Mushroom.
To the north, there is a Hiker, and if you have gotten any statues in the Grand Underground, you will get 3 Star Stickers B.
There are berry trees northeast of the Hiker.
In the pit north of the berry trees, check on the rock on the right side to find a hidden Awakening.
If you go west of the pit, then north, and ride your bike up the slope (press B if you aren't going quickly enough), then you can go northwest to find a bottle of Calcium.
Go back the way you came, and go north from the Hiker, and ride your bike up the slope (press B if you aren't going quickly enough). You will battle Cowgirl Shelley, who has a level 14 Bidoof, three level 15 Bidoofs, and a level 16 Bidoof. You get 540 Pokédollars for winning.
To the northeast, you find Lost Tower, where you can get TMs that teach Strength, a move that you can eventually use in the field after you get a certain Gym Badge.
To the east, you can cut down a tree to reach a TM47 Steel Wing.
To the northwest, you can battle Young Couple Sue and Ty, who have a level 19 Machop and a level 19 Meditite. You get 5320 Pokédollars for winning.
Go north and you will reach Solaceon Town.