I filed taxes with Credit Karma, but it got rejected twice because the IRS says my AGI for 2019 is incorrect. I decided to just file with TurboTax. Will I get penalized?

Since the federal tax return has been rejected by the IRS, then it has never been received by the IRS for processing.

You can create, complete and e-file again using TurboTax without any issues with the IRS.

However, the federal tax return can still be rejected by the IRS if the 2019 AGI is not in the IRS database for your name and Social Security number.  If rejected for the 2019 AGI try using a 0 (zero) for the AGI.

Thank you very much!

If your return did not get accepted by the IRS then you have not filed. and will not face any consequences if you file with TT. However if you use TT you will still need to get your correct 2019 AGI before the IRS will accept your return.