Hi! You and I are in the same boat! I got one for Christmas from my daughter. Actually two , a compressor and colors. The airbrush hand pieces are Master model G34 and G70. The G34 for is the regular chrome handpiece. The G70....I am clueless on... no instructions! I tried out the airbrush first on fondant covered cakes, I used the pearl luster and found that any oversprays really show up and also that lots of natural light help. Cleaning in between colors is a must. My second cake was interesting. I sprayed a car ( and I'm still learning on the settings) anyway, used just the regular blue color, and noticed the kitchen looking a teeny bit foggy haha! The airbrush worked fine on the car, but the setting caused excessive pressure??? and I discovered everything in my kitchen had a fine layer of blue. Took forever to clean up.. everything, my frig, cabinets, cords,walls, floor, sink, plantation b linds lol, you name it, it was covered!!
I will try and stay in contact with you, maybe we can learn together!
There's a few airbrush DVDs available on the market for cake decorators and there is a wonderful website called "how to airbrush .com" (take out spaces.) They have wonderful tutorials on techniques. Hope that helps! 
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