Speak with Ormak Grimshot in Orgrimmar.
You now have the power to tame a pet, but you must also gain the skills to train it.
Travel to Orgrimmar. There you must speak to one of our most revered hunters, Ormak Grimshot. He will give you the ability to train your new pet. You will find him near the Hall of the Brave.
Good luck, [player].