When you ask the horse to do something, initially, it is just that, ask. Good chance with a youngster it will be ignored. I would use leg then if no response a tap with a whip or willowy branch behind my leg. If still no response as the horse hasn't made the connection, I would continue to squeeze and tap until the horse likely scoots forward. I am careful to not pull on the reins at this time as the horse receives a mixed "go-whoa" message. If she breaks into a trot I leave her alone. It may be for only a few strides and that's a good start. I'll allow the horse to walk a minute then ask again. It takes more than a few times for the horse to realize the tap follows the squeeze and will soon break into a trot. Leg is also removed as soon as the horse trots.