There's only one mission for Pillars of the Earth right now, but it's the introductory mission to set the groundwork for that area's story arc. You can think of it as the first Story mission.

Just a quick note, you can do all the missions alone, or with other players, rewards will not be split, so everyone receives the same rewards, just remember that if you plan on going in with someone else, you both get graded the same for style and objective points too, so synergy and cooperation will basically be put into consideration for that grading.

You may start picking them now if you so please.