[Geek44]

Wolster, I'm the opposite of LT here. I hate using acrylics in my airbrush and never had any problems with my airbrush until I started experimenting with Tamiya acrylics. Sorry to add to the confusion mate.
Like LT, I use an eyedropper to add the recommended thinner...I always use a thinner by the same manufacturer as the paint I'm using. Always. I always add the thinner a little at a time. The basic rule is that the paint should be the consistency of milk, whatever that means. What I do is mix my paint in a glass jar. To see if the mix is right, I hold the jar up to a light and tilt it so that the mix runs up the side of the clear glass. I then straighten the jar and mentally time how long it takes for the paint to go transluscent on the part of the jar I just 'painted'. If it stays opaque for too long, I add a couple of drops of thinner and stir it in, then do my test again. It's kind of 'esoteric' I know, but it works for me. I might suggest trying the brush with plain water or even some thinner just to get a feel for it. Spray onto a piece of paper maybe? Experiment a little. Have a go with some paint, again on paper just to see. There are some pretty good books available that will show you how to trouble shoot if you have problems. I have a FineScale supplement that has some basic hints...if I can find it, I'll send it to you.
Above all mate, don't be intimidated by the airbrush. It can be a scary instrument but it can also be a relatively easy way to get excellent results. I might also suggest trying a simple scheme as your first try on a model. Luftwaffe and Italian aircraft still freak me out after 20+ years.
Good luck. BTW, I'm only a PM away (as I'm sure the other guys are) if you need help or advice.
Peace.