I want to file a tax return for my father who passed away last year. Can I do that and should I answer questions as my father?

Yes, you would mark in the Personal Info section of TurboTax that this person has passed away during the year and answer the questions based on your father's information.

https://ttlc.intuit.com/replies/3300219

https://www.irs.gov/uac/how-do-i-file-a-deceased-persons-tax-return