Confused and stuck :(

Hello! I usually avoid sounding like a newbie but I'm at the stage now where I'm not quite sure what to do!

I'm level 21 and have completed the Main City quests and pretty much all quests in Thanalan up to my level (except for leve, my quest log is empty) including my class quests, have also used the Duty Finder and completed what's available to me.

I've been told that there are dungeons that commence at level 15 and up and that they're first accessible via a quest. However, I can't find this quest anywhere. Have also been told that there's a quest for an airship pass that is acquired at level 15 or so, and I can't find this anywhere either.

Tried to speak to the NPC regarding Retainers and was told I'm not respected enough in the city and to visit the Adventurers Guild for a quest, which isn't there.

This is driving me nuts, any help is greatly appreciated :)

Are you sure you did all the Main quest?
Following that unlocks many things, you must follow is to unlock all of em.
Edit: Oh, on the start of 15, you have to go to La Nocsea at Alport and talk to the guy near Sasatasha.

Thanks for your help.

Turns out I had to go back to Ul'Dah, Heart of the Sworn and talk to Papashan. Thanks heaps, all sorted :)