I efiled already but my issue is I put down I received the 2nd stimulus payment when in fact I had not so I want to amend or change my taxes but turbo tax have to wait?

You cannot change anything while your return is in pending.

MY RETURN IS IN PENDING—what does that mean?

Did you e-file?  Did you click that big orange button that said “Transmit my returns now?”  If so, your return is now in “pending” on a server.  Do not try to change anything while your return is in pending.

The IRS will not be accepting/rejecting 2020 returns until Friday, February 12, 2021.  You need to watch your emails for the acceptance/rejection notice that may take until the end of the month to arrive in your inbox.  And watch your spam folder too.

When you e-file your federal return you will receive two emails from TurboTax.  The first one will say that your return was submitted.  The second email will tell you if your federal return was accepted or rejected.  If you e-filed a state return, there will be a third email to tell you if the state accepted or rejected your state return.

A state return cannot be accepted until the federal return has been accepted.

https://www.irs.gov/newsroom/2021-tax-filing-season-begins-feb-12-irs-outlines-steps-to-speed-refunds-during-pandemic