Plz, plz, plz help me with my shooting games ive got other posts of them below

ok 1st i need to make a boat i made play a frame (hit) wen a bullet i made (bullet) touches it the bullet that has been shot is a duplicate and i thought if it has the original bullet on the screen it wont work unless the original touches it. and the second plroblem is that ive got a tank that moves left 2 right on side view with the arrow keys and i want 2 make a gun nozel thing that rotates 180 degrees to the side the mouse is on. and i want that nozel to move with the tank as well can any1 plz help me???