I have completed my 2023 taxe return and i am gong to mail it in. if i find a mistake can i reactivate my 2023 tax return and make the correction?

You can amend your return. 

Once you put the tax return in a mailbox the return cannot be changed.  If you need to change the tax return after mailing it will have to be amended.

An amended return, Form 1040-X, can only be printed and mailed to the IRS if the original tax return was not e-filed. The IRS will take up to 20 weeks or longer to process an amended tax return.

Before starting to amend the tax return, wait for the tax refund to be received or the taxes due to be paid and processed by the IRS.

See this TurboTax support FAQ for amending a tax return - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-change-correct-return-already-filed/L4VjJ9BA2_US_en_US?uid=ld1n99kr

You can go back and change anything before you efile or mail it.  If you mail it and need to fix something you have to wait for the IRS  to process the first return and you get the refund (or pay the tax due).  Then you can do an Amended 1040X return.  So you might have to wait a while before you can amend.