Answer: really just a whole lot of waiting
Explanation: if you don't have the max amount of villagers on your island (10), then it's a matter of waiting for a campsite villager to stop by. if you have the max amount of villagers, then wait for a villager of yours to want to move out and don't use nook mile tickets and you should get one then. if you have the max and don't want to wait (or just want a dream villager), get an amiibo card of the villager you want, invite them to the campsite, and then you can have your least favorite villager move out after asking enough times. that should work even without the card, but whatever just to be safe
