Taxes for the surviving spouse?

Here's my nickle of advice: Give it up. Seriously. Its unfortunate our system is so complex one can't easily do it, but the stress it generates is so great, I would find a reasonably priced and trustworthy tax preparer or service and dump it all in their lap and take it off your shoulders. You're on line since you are here...does your community have a Next Door listing? There you can ask for general referrals (who is a good, reasonably priced tax preparer?) and check people out. If you still really want to save and do it yourself, at least have them do the Federal return, and then you can use that to do the city, state? Also AARP has a tax prep service with volunteers, though with COVID precautions the process may be a bit changed from the usual I understand. But they may be of some help as well. Good luck.

This is a good overview of what needs to be done:

https://www.creditkarma.com/tax/i/learn-about-estate-tax-returns

You will get good answers to this queation at www.bogleheads.org

Sorry to hear that your Dad had passed in October. His 2021 taxes [for year 2020] would still need to be done. It is 2022 taxes [for year 2021] where your Dad's tax ID would not be used unless there is a carry over due to Probate delays.

I used a CPA for my parents even though everything was held in Joint names. It was too complex for me to figure out :P