Your ID is displayed on the sign-on screen, below your nickname.
TapFriend Liston the left.
Look in the top-right corner.

Your Nintendo data pipe ID is displayed in orange.
Visit theNintendo data pipe ID Retrieval pageand follow the directions.
After you sign in, change your password to something you’ll remember.
When you sign in, check theRemember Meoption, and you’ll be logged in automatically for a month.