Without leveling jacks, you have 3 choices that I'm aware of...all 3 need some type of level. I have a set of the
graduated levels on exterior and smaller stick-on non-graduated levels in cab.
1) Idle around site finding the most level spot for your MH. I do this and usually get "close enough" for us on the levels inside cab. Close enough is usually 1/4 or less bubble out of level.
2) Some type of purchased plastic stacking blocks or ramps leveling system. My primary blocks are the yellow Camco blocks which have lasted me several years. The graduated levels will give you how much is required. I have an additional set of the orange Lynx levelers which don't seem to be as strong. At least, that has been my experience. I only use blocks in sites where #1 doesn't work.
3) Lengths of 2X6 or 2X8 lumber stacked to get you level. This is pretty much same as #2 but using heavier cut lengths of lumber. Some like this method because they have bad experiences with the plastic blocks breaking/cracking. The lumber is heavier and, IMO, more difficult to store because they don't interlock and go into a storage bag.