First off, painting and all the comes with it is a skill, not something you can just watch a video and be good at it. This seems to be lost in today's "instant gratification" environment. I have painted a number of cars but I cannot say I am good at it because I do not do it frequently and thus I have to re-learn every time.
As I think has been stated, prep is the key to a decent job. Paint WILL NOT hide bad body work or poor prep (I have found this out the hard way too many times). The equipment is somewhat secondary to the prep and materials, however you do not need a $1000 HVLP gun, I have painted several cars with the $20 HF gun and they came out good. I finally bought a $250 Devilbiss gun when I painted my Cuda a few years ago and while it worked well, I cannot say it was all that much better than the HF gun other than it was/is much more consistent and durable.
A good consistent air compressor is a must as is clean dry air (another lesson I had to learn the hard way).
Despite all of the differences in the various videos out there, the process is essentially the same, do the body work, prime the vehicle, block sand (repeat as necessary), apply top coat (clear if using 2 stage), wet sand. This said, there are many sub and optional steps for all of these such as using 2K, sealer, etc.
I will say this, do not paint your engine compartment, trunk and/or interior/door jambs and then go on to prime the outside of the car, you will blow primer into all of the things you already painted (another hard learned lesson). You can seal/mask those areas but it is a pain. Better to do your body work, get the entire car into primer, then paint whatever you want (engine compartment, trunk, etc) and then the outside of the car. I find it is easier to do an initial prime on things like the fenders off the car however you need to do your final block sanding with the car somewhat assembled (doors, fenders, etc.) and dont forget the wax/grease remover wipe down (over and over) as well as using tac rags in abundance. You cannot clean the car too much.