If the question is regarding 2018 AGI, and you didn't file a 2018 federal tax return (or you haven't filed one yet), enter 0 as your AGI.

The lifetime learning credit (LLC) is a non refundable credit.  You must have a tax liability to offset.

If you are eligible, you have answered  something wrong, in the interview. But, a lot of people are just not eligible. See https://www.irs.gov/individuals/llc

You can use this IRS tool https://www.irs.gov/help/ita/am-i-eligible-to-claim-an-education-credit