Having been there myself, I would suggest turning the power and wire feed right down. Then increase the wire feed step by step until it's not "popping" anymore. do a couple of lines, and check your penetration - is the weld going right through. Once you are comfortable with that, do the same on the next power setting. You will find the right setting for the metal that way, and the wire speed that goes with it. And just keep practising! I have only just really got a handle on our welder, and then I used one at work and it was totally different, but after a while you just get a feel for the right settings.
And just keep practising!