Question

If any object is lying down on a ground surface, what energy will it have?

Answer 1

Potential energy is not a measurable physical quantity. What can be measured are differences in potential energy. So, if you compare the potential energies of a given mass at the Earth's surface and 100m100m above the surface, you cannot choose their difference, because that is governed by the laws of physics. However, you can freely choose to assign any point in space a specific potential energy (for the mass mm). You could define that mm's potential energy at the surface is 00, or 1234J1234J, or any other value.

Kinetic energy of a point particle of mass mm is defined by mv22mv22, where vv is the velocity. "The velocity with respect to what," you may ask. The choice is, again, yours to make; for different frames of references, you get different speeds and kinetic energies, and different notions of "rest". However, as long as mm is not accelerating (and m≠0m≠0), there is always a reference frame in which v=0v=0 and thus Ekin=0Ekin=0.

So yes, for a body at rest (with regard to an inertial frame) at the surface (or any other point), you could very well claim that it has zero potential and kinetic energy.