Place your tent. Place the other tents.
Go to sleep.
The next day Tom Nook will wake you up and deliver the phone. Back in his tent he will offer tasks to complete. I assume there should be an option named "What should I do..." Tom Nook is the big racoon in the back. The one at the entrance of the tent is either Timmy or Tommy. They run the shop.
Tom Nook will gift a diy recipe. Craft the net and fishing pole to collect 5 creatures. Tell Tom Nook you "found a creature" and donate the first. You will get stuff in return. After the 5th donation Blathers will be on the phone after which you are asked to find a spot for his tent (museum).
The next day Blathers will visit and request 15 donations for the museum to be build.