After you pass through Paniola Town and Paniola Ranch, you head north to Route 5 on your way to Brooklet Hill.
The guy near the start of Route 5 asks you to defeat all the trainers in Route 5. If you do, come back and talk to him. You will battle Trial Guide Bronson. He has a level 22 Slowpoke. You get 1056 Pokédollars for winning, and he gives you TM96 Nature Power.
Go upward from that guy and you will find a Super Potion.
If you go into the grass to the right, there is a hidden Star Piece to the right, next to a big rock.
Go downward from there and go up the ramp to reach a rocky ledge. Go upward along the rocky area to find TM41 Torment. You can go to the left and jump down the one-way ledge to continue.
Go to the left from there and you can battle Pokémon Breeder Yuka. She has a level 15 Morelull and a level 16 Ledyba. You get 640 Pokédollars for winning.
You can't go farther north, because a couple of Team Skull Grunts won't let you enter the grass there. Go back down and you can battle the two kids to the left. They are Twins Isa and Nico. They have a level 15 Igglybuff and a level 15 Happiny. You get 360 Pokédollars for winning.
Go to the left from the twins. You find Hau, who has just lost against Gladion. He challenges you to a battle. Team Skull Gladion has a level 17 Zubat and a level 18 Type: Null. You get 720 Pokédollars for winning.
Afterward, there is a cut scene, and Hau gives you three Revives.
Northwest of where you battled Gladion, you will battle Rising Star Duo Lauren and Justin. They have a level 17 Rufflet and Level 17 Vullaby. You get 1632 Pokédollars for winning.
You can go back the way you came and take the lower-left path, then go up through the grass to find TM57 Charge Beam.
Go back down through the grass, then go to the left through some more grass. Up above, you can battle Pokémon Breeder Cory, who has a level 15 Paras and a level 16 Spinarak. You get 640 Pokédollars for winning.
There are berries under the nearby tree.
Go up from there to find the Pokémon Center.
Route 5 Pokémon Center
Talk to the guy holding the fishing rod to get a Dire Hit.
Talk to the guy in green, and if you have a Lillipup, you can trade it to him to get a Bounsweet named Bouncee. Lillipup can be found in the grass near this Pokémon Center. Kihei's Bounsweet is holding Bright Powder, which reduces opponents' accuracy. Bounsweet will evolve at level 18. Kihei said that Bounsweet is helpful in the next area (Brooklet Hill), so you might want to put this Bounsweet into your party.
The girl at the table says that there are many Water-type pokémon in Brooklet Hill, so you should bring plenty of Grass-type pokémon.
Talk to the researcher to the left and he asks you to catch a Feebas and show him your Pokédex afterward. If you do, he will pay you 3000 Pokédollars.
When you are ready, go outside and go into the cave to the left to enter Brooklet Hill.