You may be eligible to use qualifying widow(er) as your filing status for 2 years following the year your spouse died. If your spouse died in 2019, and you haven't remarried, you may be able to use this filing status for 2020 and 2021.
This filing status entitles you to use joint return tax rates and the highest standard deduction amount (if you don’t itemize deductions). It doesn't entitle you to file a joint return.
For more information please check Qualifying Widow(er)
If you don't have any dependents. you file Single.
That's all there is to it.
if you did not file Married Joint in 2019, you should amend your 2019 tax return.
You should start a brand new account for yourself and not transfer from last year. You can not remove a spouse or switch the order of names.
Online is only good for 1 return. But you can use the same email address for 5 accounts. How to start another return in the Online version
https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-start-another-return-in-turbotax-online/00/25596