Congratulations on beating the final Province!
There are currently no other Story Missions available, but a Season 2 of the story will definitely be coming at some point in the future.
Though there are no Provinces to be beaten, you can still complete different Quests, hunt Titans with your Alliance and keep collecting new Heroes.
Check out a super early sneak peek of Season 2 on our Community Forum!
Keep an eye on all updates - there might always be something worthwhile to check out!