Parking Problems

Cargo van? Length? Using cones? Too many variables but maybe this will help.. Pull forward till your rear guard is even with the front cones. You should be 2ish feet away from cones on passenger side. Turn wheel about 3/4 to one full turn to the right and begin a slow backing maneuver. Watching drivers side mirror while glancing at passenger mirror, when halfway past the front come you should be seeing the outside rear cone in the drivers side mirror. Now counter cut to the left till your left rear guard is aimed just inside of the rear outside cone. At this point is where drivers cut too much or not enough. Watch you right front clearance while keeping your left rear guard just inside the rear outside cone. I’m confused why no one there is working with you on this?

The school is more focused with the class a drivers, it's a box truck a little bit bigger then a u haul truck, cones are only set on the middle lane, last attempt the lift gate in the back was over the line