Where can I find the Name Changer, Move Tutors, Move Reminder, and other important NPCs?
Move Reminder Location: Mount Lanakila, PokeCenter – Right side, in a green dress.
Move Deleter Location: Hau’oli City, PokeCenter – Right side, the old man near the mart.
Beach Tutors Locations: Big Wave Beach, Heahea City Beach, Ula’ula Beach
Battle Tree Tutors Location: Battle Tree, Poni Island
Move Tutors
Hau’oli City Mall Grass / Fire / Water Pledge: Talk to the NPC on the right, in the blue shop in Hau’oli City Mall. This move can be learned by Starter Pokémon of matching type from all regions / Gens. Frenzy Blast / Blast Burn / Hydro Cannon: Talk to the NPC on the left, in the blue shop in Hau’oli City Mall. The move is only available to fully evolved starter Pokémon of the same type. It is also available to eligible Pokémon from all regions / Gens.
Hano Grand Resort Secret Sword & Relic Song: Talk to the old man in the lobby of Hano Grand Resort to learn these two moves for Keldeo / Meleoetta. These moves will transform to Resolute / Pirouette Forms in battle. Volt Tackle: Talk to the lounging Pikachu with its butler out front of Hano Grand Resort. Fend off meddlesome reporters and the Pikachu will give you Volt Tackle.
Seafolk Village Dragon Ascent: Talk to the man in the red shirt in the Seafolk Village PokeCenter to learn this move. Only Rayquaza can use it, and it is required to enter Rayquaza’s Mega Evolution. Draco Meteor: The most powerful dragon-type ability can be learned in the Seafolk Village PokeCenter. Talk to the Ace Trainer near the café. Any dragon-type can learn this, including Pokémon that can transform into dragon-type with memories or other items.
Source
Move Tutor (Pledge Moves) - Hammerlocke
Move Tutor (Ultimate Moves) - Wyndon
Move Tutor (Draco Meteor) - Circhester
Move Tutor (Steel Beam) - Monostoke
Move Deleter - Various Pokemon Centers
Move Reminder - Various Pokemon Centers
Hyper Trainer - Battle Tower
Lady Clear - Workout Sea
IV Judge Location: Route 11/12 Gate
Madam Celadon - Nature Manipulation Location: Celadon City
Hyper Training Location: Route 5
Move Reminder Location: Indigo Plateau
Happiness Checker Location: Pallet Town
Poké Ball Replenishment Location: Mt. Moon, Rock Tunnel, Seafoam Islands, Victory Road
Move Tutors Location: Cerulean City and Fuchsia City
Hope I helped!