Electrostatics is made of two words: Electro referring to a charge (or more likely a build up of charges called a net charge) and statics which means not moving. Electrostatics is charges not moving.
Objects will contain two types of charge. Either neutral (meaning the amount of positive and negative charges are balanced to a net charge of "0") or a net charge (which could be positive or negative). Charge is usually conveyed by the gain or loss of electrons which contain a negative charge. Protons do contain a positive charge, but they reside in the nucleus of an object therefore are not likely to be exchanged... unless you like very large explosions (jk!). The charge of one electron is called the fundamental charge q = -1.6E-19. The charge of a proton is equal but opposite.
Charges in proximity to each other will exert forces on each other based on the fields they create. Negatively charged particles will create a field that draws inward, and positively charged particles will create a field that pushes outward. Hence the term, "opposites attract". (Also hence the term, "like repels".) Imaginary Electric Field lines can represent the field created by each charge and how they will interact with each other, however a greater charge must be represented with a greater number of arrows since a the field lines theoretically go on infinitely in all directions. Coulombs law tells us that the amount a force between two charges depends on the strength of those charges and the distance between them. Coulombs law can calculate the force between two charges, a sum of forces is needed in order to calculate between multiple charges (see superposition of fields).
An object that gains a net charge will have an excess of charges that repel and want to get away from each other, so they will spread out over as much distance as possible. However if an opposite charge is brought near it can create polarization. A polarized object is an object where like charge is condensed into one area to produce a net charge in one area. Charge can be conveyed by touch (conduction) or by proximity (induction).
Some materials are more conducive to moving charges, we call them conductors. Its is a mark of bond type that gives a material the property of easily moving charges. Metals with metallic bonds or salts with ionic bonds are helpful in this. Insulators are usually covalent. Semiconductors are used to control the amount of conductivity, in order to control the movement of charge through things like microchips.
Circuits are closed loops where charge is allowed to flow (called current) from an area of high potential energy to low potential energy. The battery or EMF is the provider for these charges. The volume and speed that those charges can move around the circuit depend on the battery size and resistance of the circuit. The battery size (called voltage or potential) is measured by the difference between the positive terminal and negative terminal. Resistance is like friction for moving charges. Resistivity (slightly different from resistance) is the natural resistance of the material making up the wires and their size/shape/area. Movements of charges are covered by what is known as Ohms law.
There are two types of circuits: Series and Parallel. Series circuits mean that charges have the opportunity to travel back to the battery on only one path. Voltage used on this single path equal the potential of the battery. Parallel means that charges may travel more than one path on their way back to the battery (like halls in a school that allow you to get to class multiple ways!) Each branch will have the full voltage available in the single line leading to it, so current has to speed up down each branch (so resistance lessens). Generally, the less resistance, the higher the current (like a river running downhill vs across level ground.)