Right first things first getting the paint, any motorfactors can do colour matched paint for you, some can also put this into rattlecans so you don't need proper painting equipment to apply it. Some places I have even heard can do cans with proper 2 pak paint ( top coat for paints to make them glossy and pretty, comes as a base ie clear laquer and a hardner chemical to make it go rock solid. ) I personally have never used these but they do exist. due to the paining industry going into water based paints its harder to find blokes that can make up 2 pak for you but I have very little experience with the waterbased stuff and as far as I'm aware it still uses 2 pak laquers as a top coat.
As for the exac match you tend to get what you pay for GTi for example is a brand that produce paints and they are fine for quality but a little hit or miss with the perfect match, Standox on the other hand are twice the price but pretty much bang on with the matches everytime. most brands have colour charts and a lot of them have variants for each colour so check it outside with anothe panel from the bike.
start with a heavy sandpaper like 120 or 260 grit and get the whole panel rubbed down, then put on some heavy "filler" primer, let the coats flash off and go tacky before putting on another coat. Once this has set fully ( help it with a heat gun/hairdryer ) rub it down with wet 500/600 grit paper til all the surfaces are nice and flat you should see most of the primer in the scratches and damaged areas and it may need a few more coats to get it just right. spend time doing this properly as it will be what makes the job a good one. once your happy I would throw one last coat of primer at it and rub that down just till its nice and flat, usually paint will be textured when its applied, especially when done with cans, just rub enough to get the texture off and kill off all shine so the top coats have something good to stick to.
Onto the colour coat you go, start putting the paint on nice and easy, don't try to get complete coverage it should be all blotchy at this point ( this helps the paint stick to they primer, it it was once big heavy wet coat of paint it would peel off very easily and run all over the show while wet ) don't worry about how many coats you have on, different paints and even different colours all cover differently. you can speed up drying between coats by using a hair dryer or heatgun. once you have a nice colour and no light areas let it dry out and hit it with your clearcoat, unless you have a hair or something don't rub this coat down otherwise you will see it once the clear goes on and have to start over. put the first few coats of clear on like before but work quickly and don't let them dry too much, just let it evaporate off the propellant and thinners till t goes tacky, then you will need to lay down nice flat solid coats you looking these to be proper wet and look like glass, use a hand lamp to see areas there isn't enough on and be careful not to put too much on and have it running. clearcoats are much thicker than paint so you can bung quite a bit on before it will start to run, but having to sand down a panel and polish the shine back on afterwards is a right ball ache.
I would put a fair few coats of clear laquer on as its going to give you all the nice gloss and protect that paint from scrapes etc. a good way to do it is get a ton on in the evening and let it dry out well overnight and in the morning rub it down with wet 600 or higher paper till its nice and flat but DO NOT rub through the clear, go over this again with a few more coats and let it dry this should give you a nice flat glossy surface that will need very little sanding or polishing to be damn near perfect, I have aways tried to get a perfect coat of paint on last right out of the gun so there is not much need for flattening/sanding and buffing back up.
If you do need to get dirt/runs off the final coat and you still have some clear left once its sorted fire another coat on and hopefull this will be better.
If you are having to sand the finished item down then don't use anything rougher than 1500 if having to polish by hand ideally I would use 2500 wet paper and a little soap to lessen that again, it will take forever to sand the paint flat but it will be much easier to polish the shine back on
my finishing polish of choice would be farecla G3 rubbing paste, use it like a normal car polish on a dampened cloth and be prepared for a lot of rubbing but it WILL come back nice and shiny eventually ( this bit is a pain in the hole )
stand back and admire a job well done
Any hassle pm me and ill help however I can
Jeff