These forces are very large compared to gravitational forces. Carbon has 6 protons and 6 electrons. If you add electrons to an object it will be charged negatively. If you subtract electrons it will be charged positively. Demo of charged sphere- Van de graph generator.
Electric current is the movement of charge- movement of electrons.
Current flows from the positive to the negative points of a Voltage supply. Think of the voltage supply as a mechanical or chemical means of separating electrons from protons. Suppose we have a 12 volt battery, and a 6 ohm resistor in a simple circuit.