I have decided what I am going to do about my parents saying 'no' to me owning a horse?

now I know why your parents said no, you do not know enough about a horse to own one, and if you are not 18 you can not legally own a horse or anything else, your parents should just let you go live somewhere else on your own with out any support from them since you know so much more than they do. A chain link fence is going to add to your vet bills.