Now I have an idea of what to do with the area behind the machine shed.
Do not waste time dreaming about creating this food forest someday. Get to work and plant your foundation trees right away. You can add the chickens and other plants later. Trees take many years to become established and provide the maximum benefit. Worry about the chicken coop and the fence and everything else later. Get those trees planted as soon as you possibly can. This is an important investment in the future.