Where do most fighter jets and combat aircraft mostly get shot? ex: body, wings, engine area etc
It all depends on the types of weapons employed, the aspect of the attacking and defending aircraft and the off-boresight angle between the aircraft in question.

Air to air and surface to air missiles employ proximity fused HE Blast / rod or pellet fragmentation warheads in them.  They are guided to close proximity with the target aircraft and explode like hand grenades, spraying the targets with shrapnel, damaging structure, engines, fuel and hydraulic lines, even the pilot.  Sites of damage depend on the angle of missile impact as well as the proximity of the target within the lethal blast radius of the warhead and thus how concentrated the spread of the shrapnel pattern is.

Air to air gunnery is much more akin to bird hunting with a shotgun and less like modern guided weapons.  The most effective air to air gun systems against fighters tend to be smaller caliber weapons with high rates of fire and high muzzle velocities resulting in flat ballistic trajectories with good range.  The ideal gun kill is maneuvering up on the target's six o'clock and pumping rounds into the aft fuselage and engines.  High angle off kills can also be accomplished by leading on your target, then firing a burst which the target then flies through and gets peppered with rounds, again similar to hunting flying water fowl.  In an off angle shot the burst will be widespread over the dorsal surfaces of the fuselage and wings.