It depends on what kind of bike you what. You could get a racier bike that has a more aggressive geometry or you could get a bike with a more relaxed geometry. Having a relaxed geometry bike doesn't mean you're going to be slow though.

I would check out some local bike shops and ask to do some test rides. Also when doing the test ride, ride for more than a few laps around the parking lot.

You may also want to save money for other gear such as shoes, pedals, helmet, water bottles/cages, and clothing (bibs/jersey).