Your VS. Seeker should help. The Trainer Cafe between Veilstone and Pastoria should help. You teach it moves by using the move Sketch. It copies the move last used by the opponent, and you keep the move.
My Smeargle knows Belly Drum, Baton Pass, Explosion, and Protect
1. Why? Fly is a suckish move.
2. Considering that Smeargle is slower than the Pokemon using Fly, try first starting the battle with the Pokemon that knows Fly and another Pokemon that isn't the Smeargle. On the first move, use Fly and switch out the other Pokemon to Smeargle. Then use Sketch and see if it works.