Once you can shoot just by bending your knees, you will start with your jump shot. As you start to jump you will lift the ball to the proper position above your head and then from there you execute the exact same shooting motion as you have done before. You will need to practice, practice and practice this some more to make it smooth. Make sure that your mechanics don’t break down with this added step. Keep your motion smooth, fluid and aligned to the basket. Start short, from just a few feet away and as you get better move further away. For your jump you should be jumping relatively straight up and down however you will naturally move forward a bit.
Do not shoot out of your range! Trying to shoot from too far away too quickly will prevent you from learning proper technique with regard to how to shoot a basketball. If you have to change your technique to generate enough force to shoot the ball from a certain distance than you do not need to be shooting from that distance. Some young players should not attempt threes until they build up enough strength to maintain proper shooting motion.