First off, welcome. This website has a wealth of knowledge that really helped me when I began. Dive in and dig through. This forum (commuting) alone has a very large history with many helpful threads. You may be surprised how much you can learn.

Second, what is your experience level with riding? Have you riden in traffic in the past? I only ask that because for many people, the hardest part is getting over the fear of being out there with motorists. It's natural, so if that's new for you, understanding some basic rules of the road can help tremendously. Many things we all never agree on, but a few things are pretty universal; ride with the direction of traffic (right side), be visible, and ride in the way that YOU feel comfortable. Many members here (most?) will tell you to "take the lane" when you ride, as opposed to riding on the sidewalk or in the gutter. Personally, i agree, but most members here will also tell you that they have found, through experience, what level of traffic/speeds/road conditions are outside of their own comfort zone. Don't do something just because others said its the only way. There are a few good guidelines to follow and the rest you develop through experience. Again, dig through the forums and you will find lots of useful info and many different opinions.

Third, your bike. Obviously, handle any major concerns (like the wheel) first. After that, just get out and ride! In time, you will find what you like. I love my hybrid for commuting, but to each his own. Personally, I would suggest riding what you have long enough to see if you will stick with commuting. By then, you will start to learn of the upgrades you want to make.

Finally, it's always a good idea to have a plan B. A good cyclist knows how to make minor repairs on their own ride, but just in case, most of us have some form of backup plan (and may use it periodically). Get familiar with your local transit system. Have a general awareness of the local routes/timetables and it's a good idea to carry a transit pass with enough value for a one way fare (or just keep a few bucks tucked away). Or at least have someone you can call. People here always talk about the "freedom" of cycling. It's true! Part of that freedom is the confidence that you know how to get yourself out of a jamb.

Get out there and enjoy!