In Pandaria, we primarily see arcane magic be used by two organisations: The Shado-Pan, whose Omnia division includes magic-users and heavily features mages, and the Jade Temple, whose adepts can be seen using arcane magic in the temple grounds.
Furthermore, there are wandering wizards in Pandaria that your character could have learned from, a famous example being Nguyen and his four compatriots:
https://wow.gamepedia.com/Master_Nguyen
As indicated by Nguyen, the pandaren have known sorcery since at least the age of Lei Shen, meaning that you have plenty of room to devise a backstory - and since the game world only portrays a very limited view of the world, you could probably get away with inventing a master or even a mage school as the source of your character’s abilities.
Magic, however, has a fairly limited role in the larger pandaren society, which is why we have little in the way of details on the lore. Starting with the basic mage toolkit and looking from there is a good idea.