How do I go back to the beginning, when you have reached the checkpoint in the process

To start at the beginning of your tax return please follow the steps below. 

1)    Sign into TurboTax Online

2)    Continue your return by click Taxes > Tax Timeline > Take me to my return. 

3)    Once you are in your return click on the Personal Info tab. This is the beginning of the return. You may walk back through each section of TurboTax until you are ready to file.