As you move the nocking point or arrow rest see if it improves things or makes them worse. Keep adjusting until you are satisfied with where your arrows are hitting and grouping. Head in the middle of their body, balanced properly at full draw with your head in the middle of your body. Stand up straight with good posture. The biggest problem is their draw lengths are too long.
People learn to shoot without aiming.
Then you aim. And finally, you shoot. Develop a shot routine. If you shoot differently your arrows will go differently. Write your shooting routine down and then practice it.