As Donna mentioned, start out by leveling your trailer to the
refrigerator, not the floor. Most
refrigerator documentation tell you where to set the level, some want it on the floor, some want it in the freezer section. Then attach your outside levels. I put the left/right level centered on the front, the front to back one on the side, over the
axle.
BTW: Size matters, longer level are easier to read and somewhat more accurate.