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.
Whenever you want :). Which ones do you want? I caught Cobalion, Terrakion, Virizion, and Landorus with your help. I also caught a Thundurus and got a Wondercard Victini on that save file.