As you move through electrostatics, keep yourself fresh on the fundamentals of Work, Power, & Energy. So much of what is conceptually important in later material is based on what is happening with energy.

The work required to shift a system of charges from one arrangement to another represents the change in potential energy of the system. Two like charges store energy as they are moved together. With unlike charges, energy is stored as they are moved apart. Imagine yourself physically pulling and pushing charges in space to understand potential energy changes in a concrete way. When you have a good sense of the work involved in changing the relative positions of static charges, the formula for the electrostatic potential energy becomes almost like a kind of common sense.