I would give them a light polish first to clean them up and get rid of any overspray, you might even need some clay depending how good a job they did.
Then can just use any old sealant like you would use on the metal or otherwise get a specialist product. Chemical Guys Wheel Guard is a good all-in-one cleaner and sealant, but can't layer it with itself, although you can use a sealant and/ or wax over it.
Personally I am currently using SRP, CG Jet Seal and Collinites 476s, works really well almost don't even need to do anything more than blast them with a pressure washer if you don't let the crud build up.
For new paint though some say you should wait a while before applying wax so maybe just SRP/ clay as required now and then seal/ wax next wash.