Sum of column in Multi Rows

Hello, I have a workbook where I am trying to sum and average the data in each row (rowsize will vary) and place it in a specific column. For example the sum of columns in A2 will go in column AA:22 or somewhere depending on location of buttons. I am getting confused on how to cycle through each row and use VBA to find the SUM and then AVG. I tried jumping into VBA to quickly and feel I need to do some reading this weekend! Anyways, any help would be appreciated. I have included a sample workbook.