This quest is not available in game.
Report for duty at the Ironforge Brigade post near Hive'Zora. Prepare your Unsigned Field Duty Papers and obtain Signed Field Duty Papers from Captain Blackanvil and return to Windcaller Kaldon at Cenarion Hold in Silithus.
Note: Healing or casting beneficial spells on a member of the Ironforge Brigade will flag you for PvP.
Greetings, <name>. Before I assign you to more involved tasks in the war, you'll need to do your share of field duty.
You will find Captain Blackanvil's Ironforge Brigade outside Hive'Zora.
Report to him or his lieutenant, Janela Stouthammer and come back to me. I shall have a more advanced assignment for you ready.
Oh and please do us a favor and stay away from the Orgrimmar Legion. We've been forced to keep the two forces well apart from one another due to mutual animosity.