Originally I couldn't find my AGI from last year so I mailed my paper return into the IRS. I have since found my AGI from 2018 and need to enter my AGI so I can file electronically. TurboTax says that

[Country Apple]

You should only file a return once.  If you already mailed it to the IRS you should not try to file it again electronically.  At this point you just need to wait until the IRS processes it.