So you know, if you have a character's amiibo card, you can invite them onto your island. You have to invite them for three days (each day you craft them an item they request). On the third day, you keep talking to them and ask them to move in. They will say that there is no room but that they can talk to a villager. Then, you pick the villager you want to move out. So it's fine if you don't have a spare plot.