Hey any time. There are some great real tutorials around, I'll see if I can turn any up but if you just try the search bar here you'll probably find plenty of stuff too.
Is your airbrush single-action or dual? (The button moves up and down, or up, down and back to front.) Does it have a bottle or a cup for paint? Is it spotlessly clean inside and out?
Yes, really thin/light so that the darker paint underneath shows through, but is blended in.
Yes, that'd be a wash. Washes usually aim to shadow recesses and low points. There are several different wash techniques but it's usually thinned paint of a darker colour than what you're going over. Can be the same colour darkened with some black, or straight black or other contrasting colour. Sometimes applied with needles or very fine brushes directly into the line or crack detail you're highlighting. You can also apply a wash with a broad brush over a wider area then wipe it back. Results will differ depending on the surface you're going over, e.g. whether it is flat or gloss, sealed or not etc.
Dry brushing highlights high points. You typically use a lighter shade of the base coat. Your brush should be old, because you'll be wrecking it! Dip it in the paint then scrub almost all of it off onto newspaper. When scrubbing the brush deposits just a faint tinge of paint, you're ready - start painting with the same scrubbing style and you'll see high points on the prop receive a highlight that brings them to life.
Again, there's tutorials everywhere, but HTH!
