Is the tutorial separate from the main quest line? I would hate to spoil a quest :/

Do you mean rise of the goblins? The tutorial integrates into the main quest, but if you don't do it the game gives you the same starting xp and treasure as if you did play the tutorial. If you don't know the app I would recommend playing it though, even a seasoned player such as myself still needed to play the tutorial to get familiar with the app and rules adjustments.

If you really don't want to play the tutorial it won't spoil a quest.