First you need to realize that the term stabilizers are not for leveling, jacks are for leveling. Stabilizers are usually weaker than jacks and don't hold much weight, they just prevent movement. I think you want to ask if the Class C has leveling jacks. If you don't ask about them don't expect them to be there.
If you don't have an automatic system, the principal is the same as for trailers. First level the rig side to side with blocks or jacks, then level it front to back. If the unit does not have stabilizers (since they might not even be strong enough to hold up a Class C, then you'll need to chock the rig somehow. The big difference is that you can also use the E-brake to stabilize the rig.
Automatic levelers are not standard in a Class C, but it you get them, they would be good for both leveling and stabilizing typically with the touch of a button or two. But you might still want to consider chocking the wheels especially if the ground is not very even. If the jacks put the rig up so high the tires are not touching the ground, you probably don't need to chock them.
Read the manual carefully. If you have slides there's a good chance the rig needs to be level and stabilized to extend any slideouts. They work best when operated on the level and when the rig is stabilized to minimize unnecessary movement.
Best of luck with your selection.