Wow, how did pandaren go back to Novice Village?

Pandaren can't go back out of the novice village.

If it's pandaren of soil and water school, it's near the lake above Stormwind. There is an NPC in the pavilion where you can buy a mount.

If it's a fire gold faction, it's on the right side of Ogrima map, which seems to be called Wisdom Valley, and there is a mount in front of the auction house in the rightmost valley.