There's multiple fans you will have, a fan on the processor, that is guranteed. Probably one on your graphics card. You'll also have one on the power supply. And most likely at least two case fans. The case fans are cheap and easy to install, the others are not that hard either. I never changed a PSU fan though and there's a good chance you can't.
This is the one I picked up:
This link is broken, either the page no longer exists or there is some other issue like a typo.