Hi, Ohms.
First, lacquer thinner is some pretty hot stuff, and it dries very quickly. Along with this, I'd guess you may have been too far from the subject. The fine droplets have the time to dry, before landing on the surface.
Second, what you're looking for is a smooth, still slightly wet layer of paint sprayed on the surface. Being acrylic, it will appear dry in seconds. If you see it "pooling" and staying wet for some time, it was sprayed on either heavily, too close, or the pass was made too slowly.
For working pressure, I mostly stay between 12 to 18 psi, don't know what that is in Bar. Experiment a bit, you'll soon know what range you prefer, but the pressure is a big part of airbrushing.
If you can source it near you, I'd recommend using Tamiya's X-20A as a thinner. If not that, then I've had great luck with 71% alcohol, I can't really see much difference between that, or the X-20A. Some guys say even distilled water is an acceptable thinner.
As others said, lots and lots of practice will be the best way to sort out what works well, and what doesn't. Large plastic bottles of liquids are great practice subjects, as long as they are smooth and shiny, like model surfaces. Best of luck with sorting it.
Patrick