The Dream Suite lets you visit your friends’ towns without making permanent changes to them and vice versa. You can share your Dream Code with your friends so that they can visit your Dream Town.
To unlock it, you must have been mayor for seven days, completed at least one Public Work and connected to the internet at least once. When Isabelle is sleeping in the Town Hall, wake her up and she will add the Dream Suite to the list of Public Works.
You can upload your Dream Town by lying on the couch near the back wall of the Dream Suite. Updating you data via this method will net you 5000 bells each day so there’s even more of an incentive to update your Dream Town.
Once you’ve uploaded your town you’ll get your Dream Code.
Use the bed on the right side of the room to visit other people’s towns in one of three ways: you can enter a friend’s Dream Code, you can visit a random town or you can search for a town using a villager name, town name or region.
While you are in a Dream Town you cannot affect the town’s environment so trampling flowers or wearing out grass won’t actually reflect in the 'Real World'. Unfortunately this means that you can only take designs with you and not any items such as fruit.
You’re also unable to visit any buildings except for other villagers’ houses and Main Street is blocked off. You can find the Dream Code of the town you’re visiting by looking at the bulletin board next to the train station.