I've painted dozens, hundreds even of cars with a spray can with no trouble at all. In fact the only time I've ever had a problem was with an air brush (but that was using a mix of old paints and not straining it so it clogged the tip).
As dubix88 says several mist coats which I allow to flash off before adding the next. I then follow with a slower and therefore heavier final coat which goes on quite wet. It only takes a few seconds maybe (10-15) to paint both sides, the ends and the top, basically all in one go. This means that no bit is actually dry when the next is being painted so any overspray settling where you're already sprayed gets absorbed straight into it. I leave the body sitting for a week or so (although sometimes less than 24hrs if its automotive paint from a can, but definately not Tamiya) and then polish it with an automotive polish or modelling wax, this removes any light blemishes and will take out light orange peel effect if that is present.
I always paint outside because I don't have a spray booth or an extractor in my model room and "she who must be obeyed" forbids me spraying in the kitchen. I therefore have to be doubly careful that there isn't any wind which may deposit fine dust etc.
Snoopy I would strongly recommend that you get a $2 plastic toy and practice or even a plastic bottle or container. You can add layers of paint without damaging something important. It all takes practice and you need to find your own rhythm and style. Don't be put off, spray cans are easy and give superb finishes as the latest FSM shows.
Practice, practice, practice.
Kia ora,
Mark
"Time flies like the wind, fruit flies like bananas"