You can get a campsite on your island in Animal Crossing: New Horizons by talking to Tom Nook. He'll eventually mention the idea of getting a campsite, allowing you to build one.
Here's what you need to do:
- Progress through the game: You need to reach a certain point in the game before Tom Nook will mention the campsite. This includes completing tasks like building the museum and crafting a few DIY recipes.
- Talk to Tom Nook: Once you've made enough progress, Tom Nook will approach you and suggest building a campsite.
- Pay for the construction: You'll need to pay a certain amount of Bells to have the campsite built.
Once the campsite is built, you can invite random villagers to visit your island. You can also invite villagers to move in permanently if they are interested.