Where can I learn to apply ceramic coatings?

Any of the major manufacturers of professional ceramic coatings will provide training, in fact they will insist on it, before allowing you to be an agent for their product.

We would recommend contacting Autosmart who run a number of courses including machine polishing and ceramic coating application. They will, of course, teach you how to specifically use their products (which are very good), but the only barrier to entry is that you are a professional detailer.