Let me just say this straight out: unless you've already accepted a job (or internship) for next summer, you should go to your university's job fair.
I'll go further than that! If you are a student at a small university like mine, you should also go to the job fair at the large university close by!
There are lots of reasons.
First, practice makes perfect. Interviews are high stress, and most of us only do them occasionally. You may think it doesn't make sense to interview with a firm you aren't interested in. I disagree. You may be surprised and find out you are interested after all. And even if you aren't, the practice will help next time around.
Back when I was in high school, I was in the choir. Three of the four years I went to state competition with a solo (the other year half of a duet). The year I got 1 "3" (mediocre) instead of a "1" (excellent) was the year I didn't perform for an audience BEFORE the competition.
Second, this is the toughest job market in years. Perhaps your friends last year and the year before had jobs before Thanksgiving,; don't expect it to be so easy this year. The more interviews you have, the better your chance of finding a job you'll really like.
Third, I believe that you come to the job fair partly for the students who follow you. How can that be? Well, think like a potential employer. Let's say you have always come to the small campus because you like the students--even though you could efficiently hire more students with one stop at a larger school. Maybe you are an alum yourself. Let's say that this year only a few come to the job fair. Who knows why. It may be a smaller class than normal; the students may be feeling stressed. Will you have second thoughts about spending the time and money to come back next year?