The main story of Pokémon Legends: Arceus will advance in a very different manner from previous Pokémon games. Instead of battling gym leaders and an enemy team, Pokémon Legends: Arceus’ players will advance through the game by completing major missions assigned to them by the Scout Corps. And since Pokémon Legends: Arceus is a more expansive adventure game, it will also include a hearty roster of additional side quests. These side quests are called requests, and they are given to you by the regular citizens of Hisui.
To find missions, talk to everyone you can find around Jubilife Village and the Hisui Region in general. Many of them may ask you for a favor. The objectives of requests will be of a smaller scale than those of missions. They can be anything from capturing a specific Pokémon (or a number of them), finding different items, or defeating a Pokémon in battle.
Once you go into the wild and complete your task, return to the citizen and close out the request. As thanks, they will give you a reward, like potions. You can keep track of your requests and missions, as well as where to fulfill them, on your Arc Phone.