I'm a tiler by trade, and i have been laying natural stone floors for years, if you just want to get into cleaning stone floors, then all you would need is a rotary scrubber and a good wet vac. As for training there are a few places if you google them they will come up, but the courses are not cheap. You will need a basic understanding about natural stone, what cleaners to use etc, plus sealers. Ceramics are easy to clean, and some porcelain needs sealing after cleaning. If you want to get into diamond polishing and honing then that's a different ball game...you really need to know what you are doing with these machines, plus it will cost around £10,000 to set up. There is good money in stone floor cleaning, my job today was to clean and seal 35 sqm marble floor, the lady had tried everything to clean the grout and tiles, and was ready to rip the lot out....I got there at 7am stripped the floor of sealer, cleaned all of the grout and floor, resealed and polished, it looked as good as new and for that i got £450.00 plus she wants it done yearly.