After you find Nebby in Melemele Meadow and meet up with Lillie, it is time to complete your Grand Trial and battle Kahuna Hala.
Battle Kahuna Hala
After a cutscene, you can go upward and talk to Hala to battle him. If you are not ready, you can say "Please wait". If you want to visit a Pokémon Center first, go southeast from Iki Town, then when you reach Hau'oli Outskirts, go to the left to find the Pokémon Center. Or you can go to the right instead to visit Mom.
In Iki Town, if you found the bottle in Kala'e Bay after going through Melemele Meadow, talk to the woman in the southwest house to get a Stardust.
Back in Iki Town, talk to Hala when you are ready to battle him. He has a level 15 Machop, a level 15 Makuhita, and a level 16 Crabrawler. Hala can have Crabrawler use a Fighting Z-Power, All-Out Pummeling. You get 2560 Pokédollars for winning.
After the battle, Hala gives you the Z-Crystal Fightinium Z. You can give it to a pokémon that knows Fighting attacks, then use Z-Power to use a powered-up version of a Fighting attack, once per battle.
He also gives you the Melemele Trial stamp, which causes pokémon up to level 35 to obey you.
Tauros reappears, and Hala gives you a Ride Pager so you can ride Tauros. You can press Y to use the Ride Pager, then while riding, press B to dash.
Ilima congratulates you, and says to visit the Alola Photo Club to get a commemorative photo.
Professor Kukui gives you TM54 False Swipe, which is helpful for catching pokémon because it can't make pokémon's HP go any lower than 1, so you can't accidentally knock the pokémon out.
Professor Kukui says to go visit your Mom, then go to the Marina in Hau'oli City. Hau says that the Shopping Mall in Hau'oli City Shopping District is open now, as well as the Alola Photo Club.
Now that you have completed the Grand Trial, go downward from Iki Town to return to Route 1. As you go to the right, go down to the fence and you can find those rocks that Hala mentioned. Press Y to page Tauros (you can tap the circle to the left of Tauros in the list to register Tauros to the Control Pad), then while running toward the rocks, hold B to charge at the rocks and break them. The grass beyond the rocks contains pokémon that can't be found in other areas.
Go to the left through the grass in this area to find a Nest Ball.
Go through the upper-right grass, down some one-way ledges, and you find a Nugget at the end.
Go down to the lower area and go to the right. This will take you to the main path. If you go north to Route 3, you can go to the northeast corner of Route 3 and use your Tauros to break the rocks and reach TM83 Infestation.
You can also go back to Route 2, and from there to Verdant Cavern, and go back to the Trial Room in the north part of the cave, and you can go up the slope and use Tauros to break through the rocks to get a hidden Energy Root in the middle of a small ledge south of some of the rocks that you can break, and TM46 Thief at the end of the path.
If you go to Route 2, there is an area on the left side blocked by rocks that you can break with Tauros, to find a Star Piece.
From there, you might want to go south to Hau'oli City Shopping District, where you can visit the newly opened Shopping Mall and Alola Photo Club.
Shopping Mall
In the mall, you can visit the clothing store and talk to the uppermost woman behind the counter to get a Gracidea. It can be used on the pokémon Shaymin.
The antiques shop sells orbs that can be used on certain legendary pokémon.
The shop next to the antiques shop will teach special moves to certain pokémon if you meet the requirements.
The Battle Buffet is a place where you can have series of battles with various trainers.
To the left of the Battle Buffet, if you approach the stage, the janitor will ask you to help him clean up. Look around for sparkles, and after you check on one, go to Grimey the Grimer to give it to her. You can only carry one at a time, so visit Grimey after you find each one. After you get rid of all six sparkles, the janitor gives you TM48 Round.
Alola Photo Club
The Alola Photo Club is now open, so feel free to go in. You can take photos alongside any of the pokémon that you have with you. This increases your friendship with that pokémon. You can have your pokémon do battle actions or Pokémon Refresh actions, and you can do battle moves or other moves. You can adjust the camera position. You can press a button to have your pokémon do a random pose, and you can press a button to make your character do a random pose. Then you can press R to take six photos in a row, allowing you to capture your character and pokémon at different points in their poses.
You can select which photos to save, and after your first photoshoot, the girl behind the counter will give you a Photo Album so you can look at the photos that you have taken. You can use the Photo Album to add stickers and other decorations to your photos. You can choose photos to share in Festival Plaza for other players around the world to see. After adding stickers, you can save the photo as a copy if you want to keep the original version that has no stickers.
After you leave the Alola Photo Club, Hau will meet you outside. He is going to go to Big Wave Beach, where he will Mantine Surf to Akala Island.
Lillie will ask you to help her take Nebby back to its home.
Moving On
When you are ready, go back to your house and talk to Mom. After talking to Mom, if you want to explore Ten Carat Hill before you go to the next island, you can go outside your house, then go left and down to go to the Pokémon Research Lab. Go left from the lab, through the grass, and ride Tauros to break the rocks that block the path to Ten Carat Hill.
When you are ready, you can go to Big Wave Beach to Mantine Surf to Akala Island.
Big Wave Beach
If you go to Big Wave Beach, there will be a cutscene. If you go to Heahea Beach on Akala Island, you can find Samson, who will trade your Totem Stickers for special Totem Pokémon. You can reach Heahea Beach by Mantine Surfing from here.
Mantine Surfing
Go down to the beach and approach Hau to see a cutscene. Then check on Mantine to start surfing. Read the explanations to find out how to play the Mantine Surf minigame. You can talk to the swimmer on the beach to repeat the lessons. After the lessons, beware of obstacles in the water as you go.
You earn Beach Points based on your score in Mantine Surf.
Afterward, you will land at Heahea Beach.