Airship quest

I just got my ARC to level 15 but want to get to Ul'dah to start leveling a thaumaturge. I was told I'd get a quest to unlock airship travel at level 15 but I haven't seen anything yet. Is it automatic or is there an NPC in Gridania I need to talk to?

I completed my level 15 class quest as well, so just want to make sure I'm not missing anything.

Keep following the Main Scenario quests (the ones with the fiery ring around the quest icon). That will lead to the quest The Gridanian Envoy. It's a level 15 quest, but with all the quests that come before it, it's pretty common for players to be a bit above that level by the time they reach it, especially if they've been doing a bunch of the optional sidequests as well.

Oh, and if you want to pick up Thaumaturge before reaching that quest, you can go overland to Ul'dah before unlocking airship travel.
Central Shroud -> South Shroud -> Eastern Thanalan -> Central Thanalan -> Ul'dah

You'll still need airship/ferry access to reach Limsa Lominsa, though, since it's on an island and you can't walk there.

Awesome. Thanks so much for the info!