How can you convince your dad to let you get a horse?

First you need to ask yourself several important questions. Am I a good rider? Do I know how to care for a horse in every way possible? Can my family afford a horse? If you answered no to any of these questions then you shouldn't own a horse yet. If however you have been taking regular lessons, know adequate horsemanship skills, and can afford the costs then possibly you're ready. You can show your dad how mature you are and begin saving up any spare money you have. Once he sees you are really taking this seriously he might consent to it. Otherwise ask him if you could half-lease a horse to get a feel for ownership and the cost of owning. If he feels you can handle it I'm sure he will soon be helping you pick out a horse of your own.