I can not get any instance quests from the people in front of entrances. Not sure if it is supposed to be like this or not. it is like this for crete malorca madagascar
You get the daily quests from the NPCs at Athens dock or inside the Sanctum of Memories in Seville. You can talk to them daily to get the quests for the day. Each day is random land and sea instance. You can still do the instances without getting the quests as well to get extra drops and exploration points as well.
You only get one task/quest daily for the lower land & Sea and higher land & Sea instances
( I think a total of 4 possible open or in cool down daily quests)
BUT you can still do any instance... the lower instances are repeatable as many times as you want. Just click the "cone?" shaped entrance vortex thing and enter.