Your goalkeeper will have a defined area of the field which is their primary playing position. Why not divide the remainder of the pitch into defined areas (I realize this will take some time to do) A strip down the left side of the pitch; another down the right; a defensive defined area as well as an attacking area. It will develop players by rotating their positions of play so they sample all responsibilities. As they gain  awareness of space reduce the number of defined areas. All young children want to kick the ball so their natural instinct is to chase after it. The team coach has the task of re programming the child's understanding and therefore development of play.

Your goalkeeper will have a defined area of the field which is their primary playing position. Why not divide the remainder of the pitch into defined areas (I realize this will take some time to do) A strip down the left side of the pitch; another down the right; a defensive defined area as well as an attacking area. It will develop players by rotating their positions of play so they sample all responsibilities. As they gain  awareness of space reduce the number of defined areas. All young children want to kick the ball so their natural instinct is to chase after it. The team coach has the task of re programming the child's understanding and therefore development of play.