Instructions
Spend and sell 25,000 bells worth of items at Nook's Cranny. Once you accomplish this task, Tom Nook will upgrade his shop to Nook 'n' Go. Earn or spend 65,000 bells at Nook 'n' Go, and Tom Nook will expand the store to Nookway.
Continue selling and buying items at Nookway. Once you have exchanged more than 240,000 bells worth of goods at Nookway, you will meet the first requirement for Tom Nook to upgrade his store.
Talk to Copper and search for an access point to set up your Nintendo Wi-Fi Connection. He will issue you a friend code once he realizes you don't have one. Exchange friend codes with another "Animal Crossing: Wild World" player. Add the player's friend code to your friend roster.
Ask Booker or Copper to unlock the gate. Have your friend visit your town. The game will notify you of her arrival. Request that your friend buy one item from Nookway. The next day, Nookway will be closed. On the following day, you will be able to shop at Nookington's.