Recoil in Z axis

Hello everyone, I want to make a recoil for my gun but I didn't find a good way of doing it. I searched it but all of the answers are about " rotating the camera up when you shoot" or animating. I don't want to make camera go up, also I don't want to do this with animation, it's so simple, what I want, my gun will kick back in z axis when player shoots, but I couldn't figure out which way I should use, also I want a bit randomization when player shoots, I mean the weapon will go a bit right or left or up or down, it'll be random when player shoots. I don't know about recoil but I thought using unitsphere for randomization, but I couldn't figure it out. Can someone help me ? Thanks :).