Depends on your budget.
Badger, Iwata? Buy the best you can afford and definitely go for a dual action in my opinion.
Just practice on paper, card etc before you point it at your model.
I love love love, my Paasche Talon, I use it with a cheapo Harbor Freight airbrush compressor I've owned without issues for a couple years, before that I used my Paasche H and still do on occasion for thicker paints/primers.
I second all of the Iwata votes. I'm new to airbrushing and I have a couple different Iwatas myself. So far they've been very solid and have a nice feel to them.