Multiple Regression Equation

I am trying to figure out an estimate for a multiple regression equation base on all the variables. Since there is qualitative data involved, I know there need to be dummy variables for the data, but I am lost on if it is possible to get an estimate for the equation with all of the variables, or do I have to take individual estimates for the dependent variable, Total Sales and their relationship with the independent variables. In the excel sheet I did the dummy variables and included them.