Once you have eight villagers, head over to Isabelle in Resident Services and talk to her about your island evaluations. If you have been busy decorating these last few days then you should have reached a 3-star island rating!
Inviting K.K. Slider
When Nook hears of the rating, he invites K.K. Slider to play on your island! Unless there is an event occuring the following day, K.K. Slider will come to your island to play a concert.
Once K.K. Slider plays the first concert, he will play at your island every saturday from 6pm, where you can request that he plays any song he’s written. Inviting K.K. Slider is important because this is how you unlock the Island Designer App which enables you to terraform and add pathing to your island.