After visiting the Seafolk Village on Poni Island, you go north to the Poni Wilds.

Explore Poni Wilds

Go west from the entrance and you will find a hidden Pearl on the beach behind the Dancer.

Northwest of that, there is a hidden Repeat Ball.

North of that, there is a Max Repel.

North of that, there is a green sparkle for the Zygarde Cube.

At the far north of the beach, partly in the water, there is a hidden Big Pearl.

To the west, in the northern part of the water, there is a Dusk Stone.

South of that, there is a Pearl String in the water.

To the east of the beach, you can battle Ace Trainer Kekoa. He has a level 44 Skarmory and a level 45 Sharpedo. You get 3060 Pokédollars for winning.

North of the beach, on a cliff, you can battle Dancer Cara. She has a level 43 Oricorio. You get 1720 Pokédollars for winning.

Northeast of the Dancer, there is a Rare Candy.

North of the Seafolk Village entrance, you can battle Ace Trainer Lindsey. She has a level 44 Garbodor and a level 45 Toxapex. You get 3060 Pokédollars for winning.

To the north, there is a tree where you can get some berries.

East of that tree, beyond a patch of grass, there is a Max Potion.

Go south from there, through the grass, until you reach a short ramp on the left that leads to a green sparkle for the Zygarde Cube.

Go east, and you can go north to find a tree where you can get berries.

To the south, you can battle Cook Fil. He has a level 43 Parasect and a level 43 Ribombee. You get 1720 Pokédollars for winning.

Go south from the Cook to reach Ancient Poni Path.