Yes if you have the 2019 program you can fill out 2019 in it. You can use the interview steps to see how it works or enter directly into the forms since you won't be filling it. Be sure to save it. It will save as a .tax2019 file. Then you can Transfer it into 2020. Yes you can transfer from an incomplete or wrong file. Yes, You can change anything you transfer from the prior year. You can only transfer once at the very beginning before you start 2020. So if you want to transfer again or from another file you need to start a new 2020 return, go to File-New.
