My family and built a pole barn concept for a carport for a Jeep Gladiator and Ford Bronco Sport using surplus oilfield tubulars, some steel c-channel for cross member’s, and some flat bar. Used oilfield tubulars are thick wall pipe usually 2-3/8 or 2-7/7” in diameter. It is strong and cheap. We used a flat roof since our driveway is sloped. For the roof, we used standard sheet metal roofing.
It is a clear span and stood up reliably to high winds (80 mph locally) plus protects the vehicles from Central Texas hail.
For a tractor shed, after you workout the dimensions, a set of 2-3/8” oil field tubulars can work for the supports, roof linear sections, and etc. Fiberglass or sheet metal for the roof is adequate. I would build the roof at a slope. I used flat bar with rounded cutouts welded to the linear pipe sections for the c-channel that was welded to the flat bar.
A wall for the tractor shed should be simple with cross member’s to screw the wall members for attachment.
I do recommend used oilfield tubulars for pole barns, sheds, and carports in areas where it’s available because of lower cost, strength, and long term functionality.