Chapter 1: Melemele Island
Want a video instead of a text walkthrough for this part? You can find it embedded below:
Part 1: Melemele Island
After selecting a language, Professor Kukui will introduce you to the Alolan region. Here you'll be able to select a gender, skin tone, and name your trainer. Afterwards, your mother prompts you to help her get moved in. A cutscene will play introducing a strange girl running from some security guards. After a title screen, it jumps to real time and you'll be awoken by a Meowth. After a short dialogue with your mother, you'll be visited again by Professor Kukui. After talking to the professor, go back up to your room and check out the moving boxes. You'll get a hat and your bag.
The professor will then lead you to Iki Town to meet the Kahuna. Speak to the trainers along this route to learn some useful tips about gameplay (hold B to run). After arriving in town, the professor tells you to find the Island Kahuna. Continue straight and you'll catch a glimpse of that mysterious girl from the cutscene. Follow her straight onto Mahalo Trail. Follow this trail for a while. A cutscene will soon play where the girl releases a Pokemon and it gets attacked by some Spearow. The girl will ask for your help. Approach the distressed Pokemon and watch the cutscene. A mysterious Pokemon will come to your rescue and the girl will give you the Sparkling Stone.
The next cutscene will bring you back to Iki Town and reveal the mysterious girl to be the professor's assistant, Lillie. The Pokemon you saw earlier was a Tapu Koko. It's the island's guardian diety. Kahuna will then let you choose between one of three starter Pokemon. Your options are Rowlet (Grass), Litten (Fire), and Popplio (Water). After you choose your starter, Professor Kukui will give you the Pokédex and your Trainer Passport. Head south towards your home town to begin your first Pokemon battle against your rival, Hau. He'll pick whichever starter Pokemon you have the type advantage against: Popplio (you chose Rowlet), Rowlet (you chose Litten), or Litten (you chose Popplio). You should be able to quickly take him out using STAB moves. Kahuna Hala will then take your Sparkling Stone.
Afterwards, you'll arrive back at your mom's house. After some more dialogue, the professor will once again arrive at your door. Follow him right of your house to Route 1. He'll show you how to catch a wild Pokémon. He'll give you 10 Poké Balls and 5 Potions. After the dialogue, head north back towards Iki Town. You can now capture or train against and wild Pokemon you like. Pick up a Potion from an item ball near the second patch of grass. Just north of this you'll encounter your first Pokemon trainer. Defeat him and continue north. There will be another trainer here and a Poké Ball in an item ball above another patch of grass. There will be an Antidote in an Item Ball behind a fence just beyond this. Continue on, picking up another Potion and battling the trainer if you'd like. There's a Paralyaze Heal to the left. Continue north to Iki Town.
The residents of Iki Town are celebrating a festival. Continue north to see a cutscene and then begin your second battle with Hau. He'll have another Pokemon, but you should still be able to easily defeat him. After the battle, Hala will give you a Z-Ring. The rest of the cutscene introduces Island Challenges. You'll then be transported back home and your Pokemon will be healed. Lille will then lead you to Kukui's lab to the south. Continue south along this route, you can battle two trainers and pick up an Awakening from an Item Ball if you like. Otherwise, head into the lab. The professor will upgrade your Pokedex to the Rotom Dex. He'll also give you an Island Challenge Amulet.
Exit the lab and head back North towards your home, and then go left from there. After an introduction to Pokemon Centers from Lillie, continue left to the Trainer's School. The professor is waiting for you here and will give you the Exp. Share. You can pick up a Potion in an item ball on the left side of the school grounds. Head through the gate to the left and battle the trainer. Defeat his Metapod and pikcup the Antidote and Paralyze Heal below him. Head to the right side of the building, picking up the Potion along the way. Defeat the trainer on this side of the building.
Enter the building and speak to the adult to the left to get the Quick Claw. Speak to the trainer to the right of the stairs to battle her. Defeat the Bonsly and then head back outside. Speak to the male traier out here to battle him. He has a Grimer that can poision your Pokemon (antidote is useful) but shouldn't give you much trouble. He'll give you TM01 - Work Up after you beat him. You may want to go to the Pokemon Center and heal up at this point. Head back inside and go up the stairs. You can get a Potion from a kid in the left-most classroom. Speak to the teacher to battle her. Unless you picked Litten, her Magnemite will likely give you trouble. It's recommended that your Pokemon are at least level 11-12 before you face her. She'll give you 5 Great Balls for beating her. You'll be introduced to the Trial Captain Ilima.
Continue to Verdant Cavern