The easy way is a bit of an art that takes some practice.
Pull in and set up the TT (with blocks if needed) so that it tilts up a bit up on the slide side (if only one side). Then when the slide(s) goes out, the weight of it levels out the TT. You also won't have to move back and forth with a slide(s) out.
If you put your slide out before leveling, you will have to crawl under the slide to put the wheel chock on and that ain't fun in the rain. If you have electric stabilizers, you can't tighten up or loosen just one side.
New fridges will work out of level. Our Norcold manual says it will work several degrees out of level. Don't know about Dometic. The worst thing for us abut not being level side to side is that the bathroom door keeps swinging open unless shut properly. (I have a feeling the wall is out of plumb a bit.)