If you don't have an owner's manual, you can download one from Land Pride, setup is pretty universal. You want it level side to side and the front one to two inches lower so you are cutting with the leading edge and blades not robbing power dragging through the grass/weeds.
Set the desired cutting height with the 3PH then adjust with top link and move tail wheel to fit. The pivot hitch should be at about a 45 degree angle when fully lowered and adjusted to allow it to follow contours.