Heahea City

Walkthrough: After arriving in Akala Island with Kukui, Lillie and Hau, you will be met by the Kahuna of the island, Olivia, and the final Trial Captain, Mallow. After you met them, all of you will go on your way and you are allowed to explore Heahea. There are a few Shops in the city - the Name Rater can be found in the Tourist Center - which you should make sure to explore before reaching Lillie. Talk to her and them follow her to the hotel. Before reaching the hotel, you will be stopped by two mysterious trainers, who will actually turn out to be Professor Sycamore's (Kalos Region) Assistants, Dexio and Sina. You will be asked to Battle either Dexio or Sina. After you defeat them, you will be given the Zygarde Cube to start finding Zygarde cores and cells.

Wild Pokemon: There are no Wild Pokemon found in the city.

Trainers:

Pokemon Trainer Dexio - Level 15 Slowpoke, Level 16 Espeon

Pokemon Trainer Sina - Level 15 Delibird, Level 16 Glaceon

Zygarde Cells: There are two Zygarde Cells found scattered in Heahea.

Items:

Zygarde Cube - From Dexio after Battle

Lemonade - From Girl in GameFreak Building

Reveal Glass - From Burnet in Lab after defeating Kahuna Olivia

Big Mushroom - Behind Research Lab

Oval Charm - From Morimoto After Defeating Him (Post Storyline)

Shiny Charm - From Game Director After Completing Alola Pokedex

PokeMart (Throughout Game Progression):

Poke Ball - Great Ball - Ultra Ball - Potion - Super Potion - Hyper Potion - Max Potion - Full Restore - Revive - Antidote - Paralyze Heal - Awakening - Burn Heal - Ice Heal - Full Heal - Escape Rope - Repel - Super Repel - Max Repel - Honey - Adrenaline Orb

TM16 (Light Screen) - TM17 (Protect) - TM20 (Safeguard) - TM33 (Reflect) - TM70 (Aurora Veil)

Post Storyline

Details: After defeating the storyline much later in the game, you can return to Heahea and face two New trainers. These two trainers are incredibly strong, and are none other than GameFreak Morimoto and Flareon User Chad.

Trainers:

Flareon User Chad - Level 55 Flareon

Morimoto - Level 62 Kangaskhan, Level 62 Flareon, Level 62 Jolteon, Levl 62 Vaporeon, Level 62 Machamp, Level 62 Dragonite