Listen to Beachgrad05 she has come a long way! The single most important thing is fit.

I have been road cycling for more than 30 years, with a little youth racing in the early 80's. This spring I purchased the first new bike in better than 10 years and set it up myself- the wrong thing to do. It was 'fine' for a bit but after some tweaking by my shop and myself it feels VERY good.
If you cannot afford this, Bike Fit Calculator | Find Your Bike Size | Competitive Cyclist is a great calculator which will put the setup near the right area. Just be sure your body measurements are spot on so get a close friend to help.