Most people who are interested in repairing the appearance of their paint are going to also want you to take care of other things. I wish I had a graphic of my scale of car care... Basically the first little bit is just car washing. The kind of thing that guys with tanks on trailers do at car lots. They just spray things down and dry them and move on to the next one. The middle two thirds of the scale is detailing. The last part is the touch up paint and PDR type things. I work in that middle two thirds dealing with restoring the paint by polishing out swirls and oxidation as well as waxing the paint, restoring and protecting the trim, wheels, tires, glass, and interior. Engine detailing is the only part of this whole process that I've had success selling as a seperate service. I've never had someone want just the paint polished with nothing else done. You can jup into the beginning or the end of this scale, but it is really hard to find clients when you jump into the middle and only offer a small part of what is typically done.
I'm not saying that you can't make it work, but chances are that you are also going to have to have an understanding of sealants, waxes, glazes, and all the things that make paint shine as well as how to operate a polisher with the right polishes. You are also going to need to understand proper washing techniques and some knowledge of clay. If you are washing the vehicle then you'll need to at least detail the glass afterwards and I would dress the tires as well. It just snowballs from there because then you have to detail the wheels too and that all makes undetailed trim stand out, so that has to be done too. lol It is just really hard to stop with paint polishing and have satisfied customers.