If your budget is tight there is Reliable Pawnshop where you can get some good deals on used equipment. Next you will want to get a license from the U.S. Cycling Federation . The small amount of money involved helps the U.S. Cycling Federation promote and organize local and national racing. Well now that we have our bike and our racing license, it's time to train. Look at the big picture and give yourself a year or a couple of years to really see improvements.
Few people do really well at first.
My first year of racing I trained really hard and at my first race at Ault Park I got dropped in the first few laps. The next week I went a couple extra laps with the pack and now after about two years it is fairly easy to stay with the pack. What I'm trying to say is that it takes time for your endurance and muscles to get use to the stress of the up and down pace of the pack. Racing a bike is not like running where you can establish your own rhythm and keep it there. In bike racing you must stay with the pack to benefit from the riders breaking the wind in front.