The breed is not as important as the age and maturity of the horse. Generally a 10-year-old or older horse that has considerable experience and is quiet and forgiving of your inexperience will be what you need. Start with riding lessons at a stable or trainers' facility. Riding lessons will help you get acquainted with horses and various riding disciplines which will help you decide what type of horse you desire. Additionally, a professional horseman can help you select a horse that will fit you needs.