Hi Kevin.
It might well be worth the time to experment with your air brush before you tackle your first job. Reread the instructions and follow the painting techniques in your owners manual.
What I did was disasemble the brush when new so that I knew what went where and how it worked following the MFG instructions. This helped greatley as I would have lost a small seal if I hadent seen it before.
My next step was using the instruction guidlines practicing with the brush, by making small to large dots and keeping them uniform and in alignment., lines of variying widths, to learn and prevent paint blobs at the end of strokes, flaired ends on lines, splattering and grainey spray. Sounds like a lot but was only a ounce of paint and was a half hour or so, was fun to do. This will give you techniques and instantly give you great results latter as you will know not only how to do it, as well as great results.
Then followed the excercises using techniques to make cones, cubes clyinders and spheres using one color in a three diminsion effect, and that my friend was awsome to me, just using one color.
Now back to your question as I degressed a tad.
I use Badger Model flex paints as per AntionioFP45 above. When you clean the brush in warm soapy water, put the plug in the sink to capture those ity bity parts.
I have also used the cheap 44 cent acy paints at Walmart, delute with warm water untill thin. works great for scenery, blending various colors in a camo effect, also river bottoms. Buying a color wheel greatly helped me get the colors I wanted mixed. You can also experiment with Badger mixing of colors, DONT MIX DIFFERENT BRANDS TOGATHER, No …I wasent yelling guys LOL, but inadvertley did this and what a mess to clean out of the gun.
I hope the above helps and wi***he you the best. You might notice I didnt say Best of luck, as luck does not have anything to do with it, its technique and practice…and you will have a