Welcome to the board.
You need to figure out all your overheads first.
Where will you be teaching - hire of room/hall or own house? If at home, will you need extra home-owners insurance in case someone breaks something or hurts themselves?
Would they be bringing their own machine or are you providing them? What about materials - will they supply all these themselves or will this be included in the cost?
How many would you be teaching at a time?
Lots of things to consider before you can set a price. Good luck.