A good way to determine all of the forces acting on a body is to attribute at least one force to each thing touching the body and then add additional forces for things that can exert a force without touching.  The first class of forces is called contact forces and include, tension force due to a rope or string), normal force due to a surface, friction force due to a surface, applied force due to someone pushing or pulling, drag force due to a fluid, etc.  The second class of forces are called action at a distance forces and include weight force due to gravity, electrical forces due to charge and magnetic forces due to moving charges.