Confused on voltage potential
Is it based on how many free electrons are on one side of the lightbulb, for example, compared to the other?


Sorta-kinda, but I think it's more valid to think of the electrons as an incompressible fluid, like water in a pipe, and whatever is generating the voltage (i.e., a battery) as a pump.


  Can you create more voltage by loading more electrons into one side?


Yes, but that makes more sense if you're working in high-voltage low-current stuff like electrostatics -- not the kind of things that make ordinary lightbulbs light up.