The work around is to mark that you did not file taxes last year and then it will not ask for AGI. The IRS does not care what you put in that field, but TurboTax asks for AGI as a security measure when you say you paid last year. In your case as a first-time taxpayer there is no AGI on file for the IRS to check and reject your return. No is the correct response to filing last year for you.
