Potential energy is typical described in terms of physics experiments.
A child at the top of the slide has potential energy. At the bottom of
the slide the potential energy becomes zero.
For a chemical that is "shock sensitive", the products of the reaction
have a lower potential energy than the original chemical.
For a spontaneous reaction, potential energy is lost. Strictly speaking, chemists prefer to discuss a chemial reaction in terms of entropy and enthalpy, but we haven't covered those topics yet.
Potential energy diagrams are used to characterize nuclear repulsion, and at the beginning of Organic Chemistry to reactants to transition states and products.