meledward23,
The draft lever is not going to do anything unless you pull the draft control pin on your tractor...check your manual. I have yet to try box blading with draft control enabled. I think it would just complicate things.
Regarding the leveling problem, you are going to have to do this backwards. By that I mean you will have to be pushing dirt instead of pulling it.
I brought my tractor into my garage and lowered the box blade until it was just above(1/2") ground level. I moved the slider on the 3pt. lever to mark where this point is. Now find a level spot in the arena and lower the blade to the level you had marked earlier. Remember you will be backing up to the high spot you want to get rid of. Now start slowly backing up towards the high spot. You should be pushing little to no sand until you get to the high spot. The box blade will get to the high spot before the tractor will and should start pushing the mound. If the sand is packed your box blade will probably just ride up the mound, so you would need to loosen it up first.
I don't know how big the mound is but if it's wider than your box blade, I'd work the sides of it then work towards the center. When you make one pass you ought to see some progress where your blade made a pass.
I hope you figure this problem out with the equip. you got. If you do, don't forget to fill us in on the details.