Call City Hall in the towns/cities you plan to serve. Ask each city hall what licenses, insurance etc you need to work in that town. Look at a directory of your State's offices and call the one you think could help you to set up or start your business.
Training, most people have " their speed " at which they clean, some are more detailed, some are slower or faster. It seems to me you need to know how long it takes you to Clean A Desk Top, A Kitchen/Breakroom, Restroom, Trash & Recycle, Dry & Wet Mop a floor. I would ask anybody you know if you could clean their office for a week or a month, keep track of the time it takes YOU to clean each room, area. Armed with this knowledge now you can make better informed bids.
Consider calling non-profits, lots of political campaign offices opening, somebody has to clean them. Call on small offices, some larger janitorial companies have a minimums such as they only take clients with 3000 sq ft on up.
Lastly, there are lots of training videos on line, Betco has 1 and they are free. Brad bdjanitorial.com