Create An Excel number analyzer

I have an excel sheet I wish to improve. The purpose of the existing sheet was to track monthly numbers in specific activities of all salespeople. Now I wish to create the same for the entire year. The existing excel sheet is summing up the total numbers of activities and gives a total monthly. Below that line is a projected monthly goal for each salesperson (they insert the goals before the month begins). below that line is the difference between the other 2 9actual vs goal). Now, I wish to create a section at the bottom that allows to calculate the sum of each month and give a total quarterly and yearly total sum. See attached and please ONLY BID if you have Experience with Excel.