Tips for getting back into riding??? PLEASE HELP!!!?

Hi. I'm 12 years old and at summer camp for the past 5 years I have been horseback riding. I don't do any riding at home. At my house I have the ability to have 2 horses on my property. I really want to get back into riding again, but I don't know what my parents will think. I play competitive soccer and have bat mitzvah lessons weekly. In the winter I am not playing soccer except for on Sundays at like 7:15 am. I don't know If I will have enough time for a horse. I don't think I would keep it on my property, we have a barn near us. I mean, how expensive a year do you think this would be? Can anyone give me good websites for specs about horses or places online to buy, on long island preferably. THANKS SO MUCH!!