No, the electrostatic potential is not an energy. It is measured in Volts which is Joules/Coulomb.
The electrostatic potential is defined formally as the amount of work required to bring a point charge from infinity (or any agreed-upon point) to a point in space. I find the definition a bit misleading since it hints at thinking of the electrostatic potential in terms of energy.
Electrostatic potential is a property of space. In electromagnetism we often think about fields as a way to describe the effect of objects (charges of currents) on other objects at a distance. The electrostatic potential $V$ is a property of points inside the field, every point in space has a potential, and when this point has a charge in it, the potential energy of this charge is $qV$.
A nice way to think about it is the analogy with the gravitational field. The electrostatic potential is the equivalent of height with respect to earth. It is the potential energy of a point in space normalized by the field's source (which is the mass in this case).