Before you file you are given the chance to review the entire return and to make any changes needed.
Anytime you want, you can peek at only the form 1040 by going here:
My Account >> Tools >> View Tax Summary >> Preview 1040
To view your entire return using the online editions (including the state) before you file, you will need to pay for your online account.
To pay the TurboTax online account fees by credit card, without completing the 2016 return at this time, click on My Account at the top of the online program screen. Then click on Print Center. Then click on Print, save or preview this year's return. On the next page, to pay by credit card, click Continue. On the next screen it will ask if you want Audit Defense, if you do not want this option just click on the Continue button. The next screen will ask for all your credit card information so you can pay for the account.