Hi Leslie
In the techniques section of this forum Michelle Rushworth posted a question about
painting on copper.
Meanwhile, I used to work a lot on copper and I think you treat it like any other support. Make sure it has no oil on it, prime it with a paint that sticks to metal and then gesso it with several coats. If you use a solvent based primer, you will need to use an oil based gesso and then paint only with oils.
Hope this helps.