If this is the first time filing taxes, what do I put for my previous years AGI. They keep rejecting my return when I enter 0

[xmasbaby0]

There is a question that asks if you filed a tax return for 2020---say no.    If your return is still rejected with that answer or with zero as your AGI, then print, sign and mail it.

When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s.  Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS/state received the return.

Federal and state returns must be in separate envelopes and they are mailed to different addresses.  Read the mailing instructions that print with your tax return carefully so you mail them to the right addresses.

[SweetieJean]

How old are you?  if you were under age 16 at 12/31/2021, you cannot efile at all.