Owlmaster08, I have to weigh in as well, because I'm not confident you understand the risks and consequences of riding on the sidewalk. I don't know your location, but in New York State, and I would assume most states in the USA, riding on sidewalks is illegal and dangerous to pedestrians. It subjects you to ticketing, fines, and worse. It also gives cyclists a very bad name, as it makes us look like a bunch of scofflaws. Don't do it!
You are legally required to ride on the road with traffic and to follow all rules of the road (e.g., don't blow through red lights and don't ride the wrong way on a one-way street). Stay to the right of the road unless there is an official bike lane elsewhere (say, on the left). You're not in much danger of being rear-ended--the far bigger risk is being "doored" by someone exiting a parked car or being cut off by a car making a turn across your path. The key is to make yourself visible. Wear reflective clothing and make sure your bike has front and rear lights as well as a bell.
Also, remember, the more cyclists on the road, the safer cycling becomes for everyone. As others have said, read the bike commuting threads for lots of strategies and good, solid advice. You'll get comfortable with riding in the road quickly enough, I promise.
Sorry for the lecture, but this is serious stuff...