Weekly Bonus Event: Arena Skirmishes

Bonus Events have returned in World of Warcraft: Legion, and the first is underway with a focus on Arena PvP. 
What Are Bonus Events?
The Bonus Events system consists of a rotating schedule of different activities, currently scheduled to run each week beginning on Tuesdays. Each Bonus Event grants a passive bonus to a particular game activity and offers a once-per-event quest with a noteworthy reward for accomplishing a related goal. The in-game calendar can serve as your one-stop reference for the event schedule. The Adventure Guide also offers a direct link to active Bonus Events, allowing you to easily accept any associated quests.
Sharpen your swords and reinforce your boards, because you’re called to the PvP Arena for the hectic mayhem of Skirmishes.
This Week: Arena Skirmishes
All week, from anywhere in Azeroth, open the Group Finder (default hotkey: i), select the Player vs. Player tab on the bottom of the window, and then under Casual, choose Arena Skirmish and JOIN BATTLE. You’ll be matched up with teammates and provided with opponents to kill in the Arena. You can also queue for a Premade group or create your own group within the Premade tab.