Are you sure you have truly finished ARR's main story, specifically the patch stories? (ARR's original story continued beyond it with five successive patches, each one continuing on from the previous one, which 'Before the Dawn' is the final quest for the final patch scenario).

Check your journal under 'Completed quests' and 'Main Scenario' and 'A Realm Reborn/Heavensward', and if it lists the quest 'The Ultimate Weapon' as the last quest you have completed, then sadly you still have a fair way to go til you can get to Ishgard. If this is the case, go back to the Waking Sands at Vesper Bay and Minfilia should have a new main story quest for you.