Welcome to Smogon! Take a moment to read the Introduction to Smogon for a run-down on everything Smogon, and make sure you take some time to read the global rules.
Just as an FYI and PSA, if you are playing an XY metagame you should be using Pokebank, if you've played already and did not don't worry about it, I didn't specify in the OP. But yes, use Pokebank as that is generally considered the main metagame and will be come Friday.
Confirming the screenshot of Mylo Xyloto because I signed up for the SPL Farm League when I had more spare time, and then school decided to come and brain me upside the head with a shovel.