That anti-electron particle is called the positron. It is the same size and weight as an electron, except it has an opposite charge. For the positive charged proton, there is the anti-proton that has a negative charge. These oppositely charged particles are called anti-matter.
Simply so, do two oppositely charged particles repel one another?
Like charges repel each other; unlike charges attract. Thus, two negative charges repel one another, while a positive charge attracts a negative charge. The attraction or repulsion acts along the line between the two charges. The size of the force varies inversely as the square of the distance between the two charges.
Consequently, why do oppositely charged particles attract?
If a positive charge and a negative charge interact, their forces act in the same direction, from the positive to the negative charge. As a result opposite charges attract each other: The electric field and resulting forces produced by two electrical charges of opposite polarity. The two charges attract each other.