When Charizard is added to your Ride Pager, you can go to the Poké Pelago, a place where your pokémon in Boxes can go to have fun.
Visit Poké Pelago
In Pokémon Sun and Moon, after Charizard is added to your Ride Pager, you can go to Poké Pelago from your X-button menu. In Ultra Sun and Ultra Moon, Poké Pelago is added to your menu slightly later.
In Poké Pelago, you meet Mohn. He will ask you to get the Poké Bean, so tap it to pick it up. Then tap the beanstalk to make more beans fall. You will be able to get Poké Beans from the beanstalk about once a day. After that, tap the crate. You can put beans into it for the pokémon in your PC Box, and there is a chance that wild pokémon will come to eat the beans, too. Then tap the blue button in the corner to talk with Mohn.
When you view your islands, you can tap on a pokémon to see its details. After viewing a pokémon, you might find more beans on the ground.
Tap the blue button in the bottom-right if you want to develop your isles, exchange Poké Beans, or send out a Bean Bottle.
Develop Your Isles
Mohn tells you that there are five Isles that you can develop, and each one requires you to have a different number of pokémon in your Boxes and Plain Beans in your supply.
The Isles are Isle Abeens, Isle Aplenny, Isle Aphun, Isle Evelup, and Isle Avue.
At this Isle, you can collect Poké Beans and put them into the crate for a chance to make wild pokémon appear. Upgrading this Isle will increase the bean harvest. If there is an exclamation mark above a pokémon on this Isle, tap it to get a Bean.
The Poké Beans that you get from Poké Pelago can also be used to feed your pokémon in Pokémon Refresh.
At this Isle, your pokémon can grow berries, up to six at a time. Tap the berry sign to choose berries from your inventory to plant. It takes 24 hours for the berries to grow. You can tap the crate to put in some Poké Beans, which will make berries grow more quickly. Upgrading this Isle will add room to grow more berries at a time.
At this Isle, your pokémon can explore a cave and find items inside. Tap the sign to choose a cave path for your pokémon to explore. It takes 24 hours for the pokémon to return from their exploration. You can tap the crate to put in some Poké Beans, which will make the pokémon explore the cave more quickly. Upgrading this Isle will add more paths for your pokémon to explore.
At this Isle, up to six of your pokémon from your Boxes can exercise at a time. Depending on the drink that you choose for your pokémon while they are playing, they can gain Exp or increase their base stats by playing. Add Poké Beans to the crate to make them finish their play session faster.
At this Isle, up to six of your pokémon can relax in a hot spring.
You can get three Plain Beans in exchange for one Patterned Bean, or you can get seven Plain Beans in exchange for one Rainbow Bean.
Send Out a Bean Bottle
You can put 7 Plain Beans into a bottle and send it out into the ocean. Use StreetPass for a chance to receive Bean Bottles from other players. If you receive beans, they will be in the water around your Isles.