There isn't any job in particular that is going to help you get into Yale. If there are, you won't find them on a public forum and it will be strictly who you are and who you know. I think you should first worry about college long before you worry about law school. You haven't even taken your SAT exams. Where you go to college and how well you do will have more impact than some job you may have at 15.
Regarding law school preparation, for which you are at least 6 years away - your best bet is to excel at all your classes and prepare well in advance for the LSAT - Law School Admission Test. Don't wait until the last minute like I did, even though I did quite well (and still made it well within the top 10%). It was most foolish and I'm just fortunate that I performed half as well as I did. It is extremely competitive and in addition to being better prepared you will also have a much greater sense of confidence going into the exam that can help you significantly. Don't worry about what school you're going to - there are plenty of excellent top law schools to choose from. Cross that bridge when you are there. Best of luck.
