Proper site preparation is the cornerstone of condensation control. The objective is to set your building on a solid surface and to establish the right finished floor height so that your building stays high & dry.
Strongly consider having gutters and downspouts installed on your building. These help you manage the water flow that will come off the roof and send it away from the building to a location of your choice
Ventilation goes a long way towards accomplishing condensation control. Vented roof overhangs with a Venta-Ridge at the roof peak pull warm, moist air out of your building and replace it with fresh cooler and drier air.