After you file

I started the 2021 taxes and it did the transfer. Im flipping around between my kids and mine and 2020 and 2021. So, I went to wrk on 2021 more and isntead went into the TT 2020 and changed that. So, I am ok iwth filling out 2021 although I wanted to cross refernce some things wtih 2020. 2021 does in some places comapre the two but  is it using the messed up 2020 versoin ....Also I am using all CD desktop versions. 

SoI guess I can do 2021 but I need 2020 for somethings and not sure if can get copy in time from IRS and I also need to get the state as I cahnged that too! And NJ also need to fill out a form. ALt time I filled out form for IRS - I got the stuff 9 months later!