There are 80 total missions to be done within the Battersea. There are a total of 3 zones that you unlock with completion of the seasons in the Dirt Tour. 8 missions are universal and span across all zones, while the others are zone specific. To start a Battersea session, select the pyramid to the left at the dirt tour menu, and you can select the zones that you have unlocked. To unlock zones, complete seasons in the tour. To view the current mission you have available press and select the missions you want to look at.