Welcome to the Forum...
I remember wanting a horse so bad....
I can only tell you that I had to prove to my parents I was ready for the responsibility of caring for that horse.
I did that by keeping my school grades at A's & B's only.
I was in school clubs that you had to participate in community activities to belong.
I started babysitting when I was 13 during daylight hours only.
I babysat every weekend and school holiday from the time I was 14 adding the late night hours.
There was no going out with friends to hang out or get into trouble with. I watched kids Friday evenings, Saturday part of the day or into the night and Sunday I had to be home by 11:00PM so could get up for school the next day...otherwise it was common for me to be brought home around 2:00 AM Friday or Saturday by one of the adults... I saved every dollar but $10 a week which I allowed myself to spend on me... so 40+ years ago I saved nearly $75 - $100 over the weekend babysitting for several families, not bad for a kid those days.
I had chores to be done at home, every day and every week certain things were my responsibility to get done and done right.
I cooked dinner nights my mom worked late or had most of it done, table set so it was fast to finish and eat when mom walked through the door.
My sisters had other chores and responsibilities...
When I had shown my parents I could be responsible for that animal, the animal would come first in everything as it depended on me to survive... only then did my parents agree to getting... However...the deal was..
My school grades could not suffer, my chores still were the same and needed done, I still babysat just as much.
I contributed what I could toward my horses care...
What I did give up some was the community service work and some of the school clubs...my horse came first and those clubs took me away from time needed to literally take care of my horse...feed, clean the stable, clean his paddock and ride him to keep him fit and healthy.
If I did not live up to my end of the bargain, if I let my grades slip, I didn't do my chores...the horse was gone!!
No going back, no do-overs.
I was held responsible for that animal staying or going and knew it.
I wanted that horse so bad...my grades were 90 or above in everything, chores done and never forgotten, homework I fit in someplace...and still I babysat to earn and pay something toward his cost.
And I returned to certain community service work I loved...
I was busy, never in trouble. I had to much to lose to do something stupid is what I told friends..
Try proving to your parents over time you are responsible enough and dedicated enough for a live animal to be in your care...
That is where I would begin...start proving to them you're ready for the challenge.