Create an interactive spreadsheet

I would like to have someone help with adding formulas to this Excel spreadsheet so that users can input their own data under "Commission Income", "Current Retention Rate" and "Increased Retention Goals" to provide them with a personalized tool to help them achieve their goals. The look/feel/fonts can be changed -- colors should remain blue, black, and perhaps a spot of orange if helpful. This will be shown as part of a presentation then made available for attendees to use on their own.