Players can unlock Island Scans by using the QR Scanner 10 times. Players can only use one Island Scan per day, and the Scan reveals Pokemon that aren't otherwise available in the game. Notably, the Island Scan feature allows players to find and capture starter Pokemon from Johto and Unova, which is the first time players are able to catch Starter Pokemon in the wild.
Global missions are a new feature to the Pokemon franchise in which players "work together" to achieve a lofty goal and earn Festival Coins, which can be used to boost Pokemon's stats or buy certain rare items. The first mission, to capture 100 million Pokemon, was a complete bust, as players failed to reach even 20% of the mission's goal. The new global mission's objective is much more modest. If just 72,000 players complete their daily Island Scan, the global mission will be a success.
You can sign up for the new global mission by entering the Festival Plaza and speaking to the Global Mission coordinator inside the castle.