Leveling can be really easy... Here's the system I've used for years, I used it on my bumper pull and I use it on my 5th wheel...single, dual or tri-axle, it doesn't matter
First thing you need to do is get a set of "Lego" blocks:
Leveling block set
I actually carry two sets and with the 5th wheel I'm considering a third set...some I use for leveling and the rest I use to place the stabilizer jack pads on. Stabilizers become less effective the further they are extended. Their best "stabilization" occurs at about 50% extended. Use the extra blocks you carry to "build up" a base so that the stabilizers are only extended about half way.
The next thing you'll need is a good trailer mounted level... I use this one, again on my old bumper pulls and now on my 5th wheel:
Jumbo Level, Dual reading
The graduations on the level are equal to one of the Lego leveling blocks. You'll need to take your trailer out to a level parking lot and get it level using a carpenter's level. When you are getting the trailer level, use the trailer's inside floor or counter as the leveling point, not the trailer tongue as the tongue may or may not be level to the frame where the refrigerator sits, the floor inside next to the refrigerator is your best bet. Once your trailer is level, side to side and front to back, you can mount the Jumbo level. Pick an area on the front of the trailer where you can see it in your rear view mirror; doing so will allow you to maneuver the trailer to the most level portion of the site without getting out of your vehicle. Once the level is mounted on the trailer you can adjust the front to back bubble portion to read properly (instructions with level will tell you how to do it). Once your initial calibration is done, you're ready to go camping.
When you get to your campsite, look in the side view mirror (remember; you mounted the Jumbo so that you can see it without getting out of the vehicle) and usually
you can jockey the trailer around, while watching the level, to get it within half a mark. The level is set so that one mark = one of the Lego blocks. If you can get within half a marking, you are good enough to call it quits. Half a mark is only 1/2" and that is plenty level for both the refrigerator and your personal comfort. If you can't get to half a mark, it is time to use the Lego blocks. Even if the tilt isn't a full mark off, say it is 3/4's of a mark off, a 1" Lego will tilt the trailer the other way and you'll only be 1/4" off of level...see how that works? Since you've already stated you are "solo", you won't have anyone to watch your tires to say "STOP!" when you are on the block, so, lay out two blocks end to end; that way you can just pull forward or backward about 8" and you'll be straddle the two of them. Say you've done your best and you just can't get closer than two marks on the level...that's where the "Lego" part comes in...lay out several blocks one level high and then build another course on top, half a block offset so that the second level of blocks straddles the first level. That will build a 2" high ramp that you can then drive up onto. Works with single axles and tandem axles and tri-axles; I've done them all and never found a site that I couldn't get within 1/2" of dead level.
Once you are side to side level, unhook your trailer and using the same Jumbo level, look at the front to rear secondary level and raise or lower your tongue jack until the bubble is in the marked area. Once that is done, take your spare blocks and use them under your stabilizers...they won't sink into the ground and the stabilizers will be more effective.
Done...your trailer is now dead level front to back and within 1/2" minimum of being dead level side to side. Plenty level to have your refrigerator work and work most efficiently, be comfortable moving around your trailer (nobody enjoys walking on a tilted floor) and level enough that your omelets won't be thicker on one side than the other!
Here's a photo of one of our campsites...you can see that I was able to jockey the trailer around to be within 1/2" of level as there aren't any blocks under the tires and I've used the Lego blocks to put under my stabilizers. You can see that the rear stabilizers, without using the blocks, would have to be fully extended. Fully extended they would have been virtually vertical (can't stabilize when your stabilizers are like a stick) and wouldn't have had much weight on them; the blocks allow them to be angled and applying some pressure on the Legos. You never want to jack the trailer with the stabilizers, but, you do want some downward pressure to "stabilize" that corner of the trailer.
Here's a picture of my 5th wheel where you can see that I have two layers of blocks under the wheels to get the rig level and spare blocks under the rear stabilizers (5th wheels only have stabilizers in the back):