Having completed your Grand Trial at Melemele Island, the next stop in your island challenge is Akala Island, an island that hosts everything from live volcanoes to limpid pools and deep jungle. Another Kahuna is in charge here, and not one, but threeTrial Captains run trials around Akala—each one designed to test and stretch your skills a bit furthre than the last.
Your Rotom Pokédex will also update itself with Akala Island's Pokédex.
Akala Island's port city, Heahea City, is a warm and inviting place that welcomes visitors with open arms. It hosts two of the most luxurious hotels in Alola: the Tide Song Hotel and the Hano Grand Resort. Both offer lavish accommodations to help travelers relax after their long journeys.
The Kahuna of Akala Island, Olivia, may act tough, but she is a kind and seasoned Trainer, and she also runs a stone shop in one of Akala's cities. She'll be waiting for you to challenge her, but your grand trial won't be for quite a while, at least until you defeat the three Trial Captains first. Mallow is one of those captains. She and Olivia are both waiting for your arrival onto Akala Island. After receiving a warm welcome from both of them, you're free to explore Heahea City.
Stop by the nearby ferry terminal and you can purchase some Fresh Water from the vending machine.
Meet the Name Rater in the tourist bureau next. He's the one man in Alola who can help you change your Pokémon's nicknames after they've been caught.
Before heading into the apparel shop, a cutscene will play involving Lillie. After a brief conversation, she heads to the Tide Song Hotel. A man in the apparel shop wants to send you on a miniature trial. Catch a Pyukumuku at Hano Beach, then report back to the man to receive 10,000. Cat with the woman across the street from the apparel shop to receive a Rare Candy.
Carry on north to reach the Tide Song Hotel, where Lillie was headed when you last spoke to her. You'll run into a couple of visitors from the Kalos region along the way. If you've played Pokémon X and Y, you may remember Sina and Dexio. They're eager to meet you—and even more eager to test your skill in battle. You battle Dexio in Sun and Sina in Moon.
After defeating himS/herM, they will give you the Zygarde Cube. With this, you'll now be able to collect Zygarde Cells and Cores. This prize will open your eyes to a new mission!
Head into the Tide Song Hotel. In the upper left corner is a green sparkling object. This is a Zygarde Cell. Sina will contact you immediately. There are 95 Zygarde Cells and 5 Zygarde Cores hidden throughout the Alola region. Collect as many as you can. You'll also meet Lillie in here. She claims the nearest trial is on Route 4, so why not go have a look? Exit the hotel and head east to Route 4.
Connecting Heahea City to the south with Paniola Town to the north, this winding, woodsy trail features plenty of tall grass and several new species of wild Pokémon. The Trainers here seek to test themselves agains passerby as they take in nature's beauty.
Cross the first patch of grass and head into the southeast corner to grab a Great Ball. Backtrack and go up to battle a Bellhop.
Go north a little bit, then go right and you can find a hidden Tiny Mushroom in a rock. Go back and up the hill and you'll find a Zygarde Cell. Go through the nearby grass and you'll be able to battle a Collector.
Go down from him into the grass to find an Energy Root. To the right of that patch of grass near the entrance to Paniola Town is a Berry tree. Careful though, as a wildCrabrawler might pop out. After collecting the Berries, head north into Paniola Town.
Fresh Water from the vending machine.
10,000. Cat with the woman across the street from the apparel shop to receive a 
Rare Candy.
Zygarde Cube. With this, you'll now be able to collect Zygarde Cells and Cores. This prize will open your eyes to a new mission!
Zygarde Cell. Sina will contact you immediately. There are 95 Zygarde Cells and 5 Zygarde Cores hidden throughout the Alola region. Collect as many as you can. You'll also meet Lillie in here. She claims the nearest trial is on Route 4, so why not go have a look? Exit the hotel and head east to Route 4.
Great Ball. Backtrack and go up to battle a Bellhop.
Tiny Mushroom in a rock. Go back and up the hill and you'll find a 
Revive. Up ahead, there is a hidden 
Dire Hit in the line of sight of a Sightseer.
Adrenaline Orb next to the grass. Go back up and around to battle the Cook.
Energy Root. To the right of that patch of grass near the entrance to Paniola Town is a Berry tree. Careful though, as a wild Crabrawler might pop out. After collecting the Berries, head north into Paniola Town.