Old road bikes typically have a better chance of working than new road bikes (because of the clearance issues CliftonGK1 described). If you've got side pull brakes, I'd say you chances are slim. If you have center pull or cantilever brakes you can probably do it.

Other advice: just get out there and race. Most advice for newbies makes more sense after you've tried it once or twice. The biggest mistake everyone makes is waiting before they try it.