After reading this thread carefully, I feel the need to chime in on a few ill advised comments.
Spray with one heavy coat? This is one ill advised advice. Not only you're making it look worse (no it does not eat away the existing coat underneath!), you 'll end up waiting for days for it to dry - IF it even dries at all. If you want to do that, you might as well toss the kit and start anew.
There's one reason why your painting session looked like utter crap - you're spraying too close to the model. Pull back at least a foot or more away. Don't stay in one spot too long. Keep moving back and forth. Spray in several light coats until you're satisfied with the coverage. Two or three light coats is suffice. Let dry COMPLETELY between coats. No need to stick rattle can under hot or warm water. It does nothing to improve the paint flow.
Sanding to get rid of the botched heavy coat. Why? Dip in solvent that will help remove the paint for you. Easy Off, Motor oil, and what not. Just make sure you soak in detergent before doing any painting.
The comment regarding never to paint other enamels brands over your chosen enamels you're using? What's the difference? They're all the same no matter the brand. Enamel is enamel.
Priming - that is up to the individual. Some don't, some do. I like to soak my sprues in mild detergent before using primer. This helps remove any residual oils from the molds at the factory. Let it dry then prime. My go-to primer is rattle can Rustoleum wet/dry sandable primer. It lays down really nice and smooth when you spray in light coats.
And finally the old adage of "get an airbrush". I agree up to a point - IF you can afford one along with an air compressor. I started out using rattle can spray paints and never had issues. In fact, my kits came out pretty good using rattle can spray paints.
If you do decide to get one, get a starter airbrush to start with. Start out with a cheap Testors brand airbrush - or even a Masters brand or Harbor Frieght brand airbrush. But for the love of God, don't waste your time on those canned air for your airbrush. They also have air compressors as well. I got mine through TCP Global for $80.
Learn how to use one, know the paint to thinner ratio that works for you, and more importantly (and I can't stress this enough) LEARN how to disassemble and clean your airbrush thoroughly!!! Once you get the understanding and know how and confidence in using one, upgrade to a better expensive brand airbrush.
Another nice investment is buy (or build your own) is an airbrush spray paint booth. I got mine at TCP Global for around $90.
When you're ready to paint, start with a cheap kit or flat surface (styrofome cups. plastic spoons/forks, etc..) Take your time and go slow. Don't rush into it. Over time you will get the hang of it. This hobby is suppose to be relaxing, Why rush trying to get a kit done in one day?
Read Parsifal's post. He's made some very good recommendations. Good luck and don't get discouraged. Practice makes perfect.