Did you download the 2020 program ? If so why are you logging in online ? The programs are totally separate and the 2020 online version is not operational yet.
How to download
How to install on Windows
How to install on Mac
Did you install it ok? Did you enter the 16 digit License Code to Activate it? Where does it say "Start 2019"? Can you post a screen shot so we know where you are stuck?
When you start a new return the first thing it should ask is if you want to transfer from a 2019 return. It should find all the 2019 files on your computer and list them. Or you can continue without Transferring.