um.. try volunteering at an elementary school or a daycare. At thirteen, you really should be focused on your own studies and activities, or just flat out having fun. when you get more knowledge and experience, then finding a way to tutor will be a lot easier.
If u have any friends who have trouble at school tell them if u have neighbors with kids tell the parent that u are a tutorer now and if their kids ever need a tutorer that u can do it
lol i work in the tutoring center at my community college. :) dont worry. you have time