First of all, welcome to the forum.
Personally, I work in subassemblies. Like complete the motor assembly and paint it. then the complete chassis with drive shaft and paint it. You can also assemble the interior seperately and paint it before installing it in the main body. I tried to paint all the parts on the sprue once but I didn't like it cause it is harder to get a clean job. You have to sand the paint down to the plastic where you must glue the parts together and sometimes it is hard to do afterward. And you'll have to repaint a lot of areas anyway at the end.
So I think subassemblies is the way to go.
Concerning drybrushing, you can use any type of model paint, what's important is to use relatively wide paint brush that you dip in the paint and then brush strokes on a piece of clothes until there is almost no paint left. Then drybrush some raised details on your model and do the whole process again when no paint comes out. You can practice on an old plastic toy first, that helps to get the feel of it.
Hope this is of some help.
No matter where you go ....... there you are.