I requested my 2019 efile tax return by mail from the irs do I wait for it to come to continue my 2020 taxes?

I wouldn't. It appears they haven't even processed returns yet (making your AGI=0 from last year). So if you requested a copy from the IRS, you might be waiting well past 4/15 and then you get penalties. :( Seems the worse the government is, the more you have work to make up for it. Never on them, always on you.

Request a transcript of your 2019 tax return online.  If it has been processed, you will be able to see the 2019 AGI for use with your 2020 TurboTax filing.  Follow this link to get an online transcript of your return.

The pandemic has affected your taxes in many ways. Including reporting in TurboTax the amount of stimulus money you received. Click Here for more information on how the Pandemic affected your 2020  taxes.