How do i convert my 2020 return to pdf? (before I actually file)

You have to pay the TurboTax online account fees before the complete tax return can be viewed or downloaded as a PDF.  Or if you are using the Free edition and do not owe account fees, the Free edition must be registered in the File section of the program.

To pay the TurboTax online account fees by credit card, without completing the 2020 return at this time, click on Tax Tools on the left side 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 Pay Now. The next screen will show a review of your Fees, click on Continue. Complete the next screen to pay by credit card and click Continue.

Click on the FILE tab(6th category when you are in Turbotax) and click on Print/Save for your records, then click on "Save a PDF", you can determine whether you want to save the file in another directory or your turbo tax directory on your computer.