Hi! I saw you're looking on how to figure out your 3ds code.
This is from Nintendo UK but would work anywhere:
https://www.nintendo.co.uk/Support/Nintendo-3DS-2DS/Usage-/Friend-List-/Viewing-your-friend-code-/Viewing-your-friend-code--240210.html
This is from Nintendo UK but would work anywhere:
https://www.nintendo.co.uk/Support/Nintendo-3DS-2DS/Usage-/Friend-List-/Viewing-your-friend-code-/Viewing-your-friend-code--240210.html