Western horseback riding usually requires using the neck rein to steer the horse instead of the English way of using the neck rein. Use the opposite rein to move the horse in the right direction with helpful advice in this video on riding and caring for horses.
With the western horse we like for our horses to move off the neck rein which is different from the English world where they like to move their horses mostly off the direct rein. With the neck rein, you are using the opposite rein on the neck to go the direction you want to go. So if you want to go to the left you are going to use your right rein against their neck and ask them to move over and move their shoulders.