Hi everyone, I'm looking information about how to start legendary quest to be able to buy stuff from the Black Prince quartermaster and don't know how to talk to them or something... i checked wowhead but the npc giver to start the quest isn't working here in warmane though, any advice, or a "where should I begin" will be appreciate.

So far I know where them are and also when I kill "Ancient mogu spirits" at "Tu Shen Burial Ground-Vale Of eternal Blossoms" i gain reputation with them

but although im at the moment friendly with them i can't speak with them or see what they sell...