Please dont use spray paint. I do automotive refinishing. you need to scuff the whole car.
If your going for perfection you are going to want to look for the high and low spots on your panels, from dings and dents if any. Go to your local Napa or mom an pop paint shop and get you a thing of bondo (body filler). If you want to do this step, let me know in this thread and I will post more detailed info.
If your not worried about the dents and dings then just scuff it, tape and paper off all your trim and anything you dont want painted. DONT half ass it, over spray will ruin everything. You're going to need a spray gun/cup, an air compressor and 400 grit sand paper to sand out the primer. You need to get a spray primer that you mix yourself and use with the spray gun.
Watch youtube for spraying techniques.
Will upload some pics of a project tomarro, might help