High Prefect Castor:
To meet the qualifications to become an Shaman, your level must be at least 20 and you must pass the Test of the Shaman.
However, it seems that your level is not high enough, and you have not yet passed the Test of the Shaman. First, work to raise your level to 20 or higher. To take the Test of the Shaman, go to Tataru Zu Hestui of the Orc village. He will tell you everything you need to know. After you pass the test, come to me and I will change your profession. Use the Gatekeeper to go to the Orc village.