Outland Shop becomes available when Outland unlocks at team level 25. You can find it by clicking the Shop tab in the upper right corner of Outland:
You can also select the Outland Shop tab when you open any other Shop:
Here you can spend Outland Coins to purchase Skin Stone Chests, hero equipment and Soul Stones of Luther, Qing Mao, Jorgen and Elmir.
New goods appear every 24 hours at 9 PM your local timezone. Also, you can refresh the Shop using emeralds.