You can not open a pdf file in Turbo Tax. You might be able to Transfer the prior year pdf file into the current year. But it is very limited. You really need the .tax2019 file to transfer to 2020.
Transfer pdf to Windows Desktop
https://ttlc.intuit.com/community/entering-importing/help/transfer-last-year-s-return-to-turbotax-fo...
Transfer pdf to Mac Desktop
https://ttlc.intuit.com/community/entering-importing/help/can-i-transfer-from-a-pdf-to-turbotax-for-...
If you can’t transfer it to the Desktop program you might be able to transfer it into the Online version. Then you can move the online return to the Desktop program without paying for online. Online looks like it takes more kinds of pdf than the Desktop program.
https://ttlc.intuit.com/community/entering-importing/help/how-do-i-transfer-last-year-s-return-into-...
