I've done a couple of cars in paint and done some body work. I did all the work on the Falcon. You can tell I'm not a metal expert LOL. BUT - it was OK for me. It needs a full sanding down and a re-shoot but the wifes racer needs it worse. The hood on the car is a Crites scoop bonded to a US Body 'glass hood, all done at home. The paint you can do for sure, and it'll teach you great respect for the pro painters. I did mine initially with a conventional gun and 1 1/2 gallons of two stage DuPont Fulthane paint. Huge mess, three coats and it actually stuck to the car. And in spite of heaving masking all over the shop, to just about everything else LOL. 4 hours in a paint suit in 95F weather is unpleasant. The prep work takes forever but makes or breaks the job. I have done later repairs to the car with my $99 no name HVLP gun and make it look good. Go to the wrecking yard (or maybe hit up a local body shop) and get a few common (cheap) dented fenders and maybe a hood for practice. Use materials from the same paint line - PPG, duPont, etc so you know they will work together.
Also - I have yet to go into a pro auto paint shop and not have the counter guys be all ready to help you out on a project. Best source of info. Place I worked with in Houston even offered to set me up in a PPG class held by PPGs rep. We moved before I could take advantage of that deal.
I have not done base-clear yet. IMHO The two stage stuff is good to learn on because if you screw it up, just sand it down and do over. I re-shot the tail end of the Falcon 3 years ago to get rid of all the burnout rock chips and misc damage. It was winter and I mixed up with the correct reducer and had heat going, but turned out the metal was too cold where I had to work. What looked great after two coats turned into a giant run fest after about 15 minutes. Well s#$t. What to do? Ah, "easy" fix - mix more and shoot the hell out of the *** end of the car, let it dry a day then start with the run trimmer, then 220 wet, 320, 400, 600, 800, 1000, 1500. After about a day of sanding, hey looks pretty good. Shiny too.
Here's the hood after laying down some Fultane white with the HVLP gun. Spent about a week on bonding the parts and smoothing the transition. I don't sand anything after unless it's really screwed up.