Configure an internet connection on your 3DS From the 3DS Main menu, Go to System Settings (Wrench icon) -> Internet Settings -> Connection Settings Click 'New Connection' -> Manual Setup -> Search for Access Point Click your Wifi name, and enter your password Ensure the test connection succeeds. Add your Friend From the Main menu, click the 'Friend List' icon (the Orange Smiley face) Give your friend your 'Friend Code', and ask for theirs Click 'Register Friend' -> via Internet and enter their friend code Go to Festival Plaza in Sun/Moon Start Sun/Moon, load your game, then open the Menu Open 'Festival Plaza' - by default it's on the second screen of options Notes: You will need to go through a short tutorial if you haven't opened it before Festival Plaza will be enabled once you are a little way into the game. If you don't see it, continue the story and check after you visit the Professor's house for the first time. Connect Sun/Moon to the internet On the bottom screen there will be a "Connected to local wireless communication" message. Ignore this. You are not connected to the internet at large and thus cannot trade with your online friend just yet. Click the 'Wifi' symbol in the bottom-right of the bottom screen. Follow the prompts to connect to the internet Once connected, the message will change to "Connected to the Internet" Finally, Trade On the bottom screen (still in Festival Plaza), click 'Trade' Click 'Link Trade' Assuming your friend is online, they will show up in the 'Guest List'. If you've interacted with them before, they will likely be in the 'VIP List' Click your friend's name and follow the prompts. shareimprove this answer