All products should say how many are included in the name. For example, Traxxas 3x10mm Fine Thread Cap Head Screws 6Pcs will come with 6 screws in the packet.
These are not precise terms (for example, not all 'fine thread' screws are the same). In general though, fine thread screws thread into metal parts or a nut where as coarse thread screws thread into plastic parts. Coarse thread screws are almost never used to go into metal parts, but fine thread screws are occasionally used on plastic.