Mozar, can you see what's underneath the wood? Ie, is there a subfloor under the wood? Can you see anything from the ceiling below?
You can definitely buy self-leveling compound that you can put over the vinyl to get a level surface, and then put a floating floor over top. That's usually engineered wood or laminate. With hardwood, you usually have to nail it down, and you need to know what you'd be nailing into. Carpenter husband says your pic of the wood slats looks like 1x2, and if that's simply attached to the floor joists, then you may need to lay a subfloor (plywood) down first. Then the problem may be that the thickness of the plywood raises the level of your floor, so it depends whether that's an issue in your space.