translate on mouse click

i am trying to write a game as bellow:
there is three targets that u have to hit them by a missile. the target are on the top of the screen and the missile on the bottomn blew a line.
I have so far drawn the targets, the line and the missile which the missile can rotate too.
now, I have to problems. fristly I don’t know how to move the missile along the x-axie by mouse click and how to hit the targets.
I will be gratefull if anybody helps me.