Juniors should learn to practice like the pros do, and that means starting with a wedge, establishing contact and hitting your driver last
Hitting the sweet spot of your putter has three advantages, it comes off the face more consistently, with more energy and has over spin instead of side spin
It is much easier to aim at a target that is closer to you than one farther away, so pick an intermediate target a foot or two away from your ball and square your putter up to that spot and use the hole for distance control purposes