When you complete the weekly Island expedition quest , which is to collect 36000 azerite. You usually get rewarded with azerite and 1500 rep for honorbound. As for your question on Darkshore, Darkshore is currently belongs to Alliance as of right now and you will not get any world quest from their anymore until horde contolls darkshore again. Go to Arathi higlands instead to do their world quests.
I would also to like to add is that check your mission table for honorbound rep tokens, they can make a big difference when you’re grinding for rep.