Hello Lizzy !
It depends what kind of tack and stuff you want to buy. Of course, if you are looking to buy a 2000 dollars saddle, it is going to be tough, but maybe if you babysit children, give classes of English or math or any subject you are good at, or do some cleaning or chores for neighbors, then you will earn some money and be able to afford a bit of equipment.
I wasn't planning on getting a horse (anytime soon) but thanks anyway for the tip!
It's probably best not getting a horse until you have a consistent income. They are expensive animals and the one of payments (horse, tack and so on) are the cheapest part.
Instead, if you are good enough, ride out other people's horses for them. Volunteer at a yard. Find a job in a sales or livery yard. It will stand to you much more in the future.
Do you already have a horse?
I don't have the money for a horse
Get a young ottb train it and sell it