What tennis racket should i get?

I'm a freshman in high school and am trying out for my high school team in the fall and want to get a new tennis racket. I now have an oversized tennis racket with a terrible grip and I really wan to to get a new one. I don't wan't to know what brand to get but an actual model. What size should i get? What strings? I am intermediate and am going to get lessons for the next three months before tryouts. Please be as specific as possible.