Congratulations for having bought our amazing airbrush !
I see you are learning the hard way. Well, my first advice will be : patience and a light hand, as an airbrush is globally fragile ( more than a sledgehammer).You don't have to force to disassemble the beast and to built it back, or something is going wrong. Check if you have a teflon seal, or not, that will determine what you can spray ( lacquer thinner, etc... ) as rubber seals don't like "hard" products. It doesn't forbid you to use enamels, anyway. It seems that it is a double action, so the average use is: push the trigger for air, then pull it back to disengage the needle from the tip so the spray widens; you must practice to feel it; nature of what you spray ( water, ink, acrylic, enamel, nail polish, etc... ) influences the result in terms of grain( I mean how much the pigments are ground ) and viscosity so it is most an affair of training. Air pressure is most important so your next buy should be a ( silent ? ) compressor with regulator, water trap, tank, etc... This compressor does not need to be a huge industrial one unless you need it for something else. Alternative is air tank, CO2 bottle, etc...
As for fragility needle and nozzle are among the most fragile so careful with them, but you don't need to be a brain surgeon to manage it. Avoid to soak your entire airbrush in lacquer thinner for instance ( Aztek owners are the only persons in the world allowed to do so ) as it is unnecessary: ultrasonic cleaners do it better.
Well, that is all I see at the moment, but no doubt there are a number of chaps who can add valuable information.
Even if you find it hard now, go on : pleasure comes after pain ( no sexual hint at any time)