I assume it all needs painting so
Any auto paint if its a metal if GRP then contact the caravan manufacturer.
If metal and full spray job then you will need Primer for any bare areas if none then leave out primer, Undercoat, finish coat, and lacquer. Coarse, medium and fine carborundum paper commonly called ‘wet and dry’ at least two sheets of each a bucket for the water to dip the paper in and roll of paper towelling. Finally hire a paint spray machine.
Coarse for key used dry. Medium wet and fine wet on top coat. Finish off with lacquer do not rub this coat down. Make sure you clean and allow to dry after rubbing down each coat or the paint will peel off.
If patch spraying use the standard auto spray cans same process. This is better than brush applied cellulose paint which unless you are good leaves brush marks.
bob, April 2011