You do not need to start over.
If the only income you entered into your return was Social Security, then you do not need to file a return. It is telling you that the Form 1040 (the main tax form that you are filling out by using TurboTax) is blank because your Social Security income is not taxable since it is your only income.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"