Your town will accomodate 9 villagers automatically (random villagers will move in and out between the space of 3 to 9 days - this is known as a cycle).
Upon building a campsite (different from the campground), you can receive random campers that you can invite to move into your town. This is usually how you fill the 10th villager spot in your town (the maximum amount of villagers is 10).
Note 1: You can build a campsite from Public Works Projects (PWP) catalog by sitting on the mayor's chair in the town hall after you get a 100% citizen satisfaction level (speak to Isabelle at the counter).
Note 2: Speak constantly to the camper and they will eventually move in despite the constant rejection.
If you want to receive Cherry, make sure you currently have 9 villagers in your town, no camper is moving into your town and your streetpass is off (avoid getting villagers from the VOID) by April 25th.
Do you still want to get Cherry? I can check back to you daily if you have any other questions regarding about villagers movements.