Re: Saving Up!
One of my daughters used to do the ironing for me once a week which I paid her to do (not a lot but something!). Washing cars...cutting grass...babysitting (for friends and family only as technically speaking that's probably not legal for someone to "hire" you at your age)
In the short to medium term though, do consider looking for a horse/pony you can share one or two days per week. This normally costs about £20-40 - not much more than riding lessons and you normally don't have to pay for anything else - you may have to do some mucking out or poo-picking. The great thing about this is that you get experience of "your own" horse on a limited time and cost basis so that when you can eventually get your own, you'll have a much better idea of what's involved.
I begged and pleaded for a horse from about the age of 4 but didn't get my first horse til I bought it myself at about 20. It was a shock to realise just how expensive everything was but at least now with forums and the internet you can get a really good idea of what the actual cost is likely to be. Be warned though, most of us deliberately DON'T add it all up as we'd frighten ourselves if we did!
What county are you in? Maybe someone here might appreciate some help in exchange for a ride or two... DON'T give any more local info than that as obviously not everyone is who they seem! ;o)