Ok
1) press x
2) go to your bag
3) go to your key items pocket
4) scroll down to your pal pad
5) then you can see your friend code or add a frends friend code like this.

Hit "See my friend code" for your friend code

Hit "Add new friend code" then add name and then
the friends friend code

If you dont have our pal pad do this

1) go down stairs in any pokemon center
2) then a girl will talk to you and give you your friend code

If your friend code isnt there do this

1) go down stairs in a pokemon center
2) connect to wifi
3) disconnect to wifi
4) look at your pal pad
5) go to your friend code and it will be there

You need it so you can do online trades,battles and other things and etc.

Lol Yh i all ready new Bes u found ur dimond yet