If you've never used, or operated a larger scraper, do not take cuts side by side. Make a full pass through on the length of the cut. With this scraper, if 3' wide, I'd guess skip 24"-30", and make another cut. Try to take the same amount depth of cut. Then come back, and pick up that 24" to 30" of material. That keeps the bowl fairly level, and the complete cut across more level. If you cut side by side, with the wheels outside the cut the bowl makes, it will tilt it to one side where you've already made a cut, and cause the cutting edge to gouge in on the lower side.
Depending on how much disked material you have on top, I'm thinking you'll be doing some spinning. Depending on the terrain, you could feather the brake on the spinning side to get an equal pull on the wheels, or, if you have a differential lock, use that. Just be sure and lock it before it spins, or stop to engage. Stomping on the diffy lock when already spinning a wheel can cause damage to the locking mechanism, if you didn't already know that.