How can me and my mom start a decorating business?

How can me and my mom start a decorating business?

So me and my mom have been thinking about making a business. We will decorate parties any kind of parties and just tell us whats the theme and things like that but I do not know how much money are we suppose to ask for?
Thanks and please answer a real answer not some kind of jibberish please. :)

Usually, you based it on how much you are going to spend on raw materials to be used in decorating the parties. The overall cost of raw material plus 50% to a 100% for your labor cost