USC Admissions??? please help?

I am going to be a high school senior and I am currently looking at applying to colleges. I love USC, its just one of those places where I feel I could fit in. I have a 3.8 GPA, and a 27 on the ACT. I play varsity volleyball and played JV basketball at my high school. I will have taken 3 AP cles by the time I graduate, and one honors cl. I have hundreds of hours of community service. I am involved in Model UN, Spanish Honor Society, Yearbook, Yoga Club and California Scholarship Federation. What do you think my chances are of getting in? What has more weight on the application? And what topics do the admissions committee like to see in the essay?