§ {Activity: Visualization of Potentials} should have given you practice visualizing electrostatic potentials due to some simple charge configurations. Some things that you might have needed to pay attention to are:

1. The electrostatic potential is a scalar field, not a vector field, i.e. it is a number at every point in space, not a vector.
2. The electrostatic potential at a given point due to several discrete charges is the scalar sum of the potentials due to the separate charges.
3. These examples are inherently 3-dimensional; drawing in three dimensions may be more challenging than visualizing in three dimensions.
4. The potential is typically not zero at a point where the net electric field or the net force on a test charge is zero. Don't claim that the potentials “cancel” just because the forces do.
5. Pay attention to how the shape of the equipotential surfaces is related to the “shape” of the charge distribution.