Route 204 is split into two sections by the Ravaged Path. The southern part of Route 204 has several trainers and wild Pokémon like Budew and Combee. Collect items and battle trainers to strengthen your team.
Enter the Ravaged Path. Here, you'll need to use Rock Smash (HM06), which you can now use thanks to the Coal Badge. Smash the rocks to clear a path. You'll find some items here, including a Potion and a TM39 (Rock Tomb). Continue through the Ravaged Path to the northern part of Route 204, then proceed to Floaroma Town.