Go next to it and press the A button. Sometimes it may run away from you (for some reason,
happened to me a few times) but just run after it and press the A button.

but it runs away from me all the time! ...****** horse... lol

go up to it,press A. if it runs, press L 2x

one easy way to get on a horse is to put it in your horse barn/house and you press a near
it then you ride it out the barn and your riding it (to put the horse back in the barn
push it in the barn you cant ride it in only out)

i've tried all that, but it still won't let me! do i have to wait a year or something
before i can ride it?

i figured it out, i had the one touch glove thing equipped. so thats why it didn't let me
ride my horse

You can't ride your horse if you have the Touch Glove equipped. That's probably why you
can't ride him. If that doesn't work, then try unequipping everything. If that doesn't
work, then you're on your own!