My return was rejected due to my 2019 agi not matching. I filed on 10/15/2019, is that why it was rejected? Should I fill it out with 0?

The IRS requires your 2019 AGI to verify your identity for e-filing. If you're paper-filing your return, you won't need your AGI because those are manually processed.

Please follow the instructions here on locating your AGI. See the information here for steps to correct your AGI on your tax return.