As said get a book, or a mate who can weld, mig is very easy, by reading the welds it will tell you what is happening.
The art of mig is correct set up, most particularly wire speed, as this has a massive influence on the work produced, look carefully at what the wire is doing when it hits the weld pool, if for example it is stuttering back and forth or you can feel it pushing you eithe rhave too much feed or too little current.
Aim for sizzling sausages sound if too much current it will tend to blow holes or make welds flatten.
I would just practice as this is the best way,
tabetha