I've been using an airbrush professionally for about 20 years or so and it is without a doubt the most complicated art tool I've come across. It behaves nothing like any pen, pencil, or brush. Just learning how to make a line where you want a line can take months. I still miss from time to time. I started in a mall kiosk painting the cheesy stuff and moved into signs and murals. Lately I've been doing more photo realistic portraits than anything else.
You've already discovered the importance of masking and using stencils. You won't get far without them. If you use the right mesh fabric as a stencil, you can make very realistic looking snake and fish skin patterns. There are some other tricks for achieving different textured looks that will be really useful. Lot's of good youtube videos out there explaining how different textures are achieved. If you ever have a question feel free to ask.
Try not to get discouraged. It can be frustrating at times. The airbrush is a finicky tool to say the least and a higher end double action brush requires finger dexterity that takes years to achieve. Proper stance and grip are the first major thing to learn with regard to form. Learning the different strokes and lines is like learning to write in cursive. Lots of repetitive loops and zig zags until it's second nature. A roll of cheap paper towels is a good thing to do these types of exercises on. I put a dispenser right at the top of my easel and a trash bin right under it.
Complete mastery of this tool would take a life time if it can even be done at all. It's a good thing it's fun to use even that first time. Enjoy, they can do some really impressive things.
PS. I can tell you how to do the copperhead pattern when you think you're up for it.
