Old horses have been there and done that they know what they are doing
Older horse that knows much more than you. I learned everything on a mare that is way smarter than I am and she made me the rider I am today :))
Older horse I would say around 13 or 14 because they don't need as much time and they know what there doing so you can just let them do their thing while you focus on getting more experienced!
Older horse. Because u can just get work on you not the horse.
Older horse!!! They will be able to teach you, and help you learn new things. A young horse YOU have to teach. Get a horse maybe around 9-15 years old. Maybe a schoolmaster or just a well experienced horse that will teach you and you feel confident on. You don't have to get a horse between those ages, that's just a guideline for me... good luck!