John, to my way of thinking and what I have found in practice, good though they are, you don't neccessarily need all this and that pigment and other such stuff. Perfectly acceptable results can be obtained without them. They can aquired when you feel ready to.
Similarily an
airbrush, I don't have one, but when you feel ready to get one the lads on here will tell you all you need to know about them.
You say it's your first time modelling, so the only advise I can give is take your time. Just look, learn and enjoy. That's why we are all here!
Don't get frustrated when your efforts are perhaps not what you wanted. You will do better with the next project.
The main thing, as John (Centurion3RTR) always says is...Have fun.
Ron