After you file

TurboTax and the IRS save returns for seven years.  After that they are purged.  Did you save paper copies of your returns?

You might still be able to get to a 2012 return--it's iffy-- if you know the exact account and user ID you used to prepare the return.  Or if you used desktop software the tax files are only on your own hard drive.

Many people have multiple TT accounts and forget how to access them.  Log out of the account you are in now.

Account recovery

https://myturbotax.intuit.com/account-recovery/

https://ttlc.intuit.com/questions/1901535-forgot-your-turbotax-online-user-id-or-password

Or did you use the desktop version of TurboTax?  If so, the files are on your own hard drive or any backup device you used like a flash drive.

https://ttlc.intuit.com/questions/1901486-how-many-turbotax-accounts-do-i-have

https://ttlc.intuit.com/questions/1901535

https://ttlc.intuit.com/questions/1901659-find-your-tax-data-file-in-mac

https://ttlc.intuit.com/questions/1900721-find-your-tax-data-file-tax-file-in-windows

To get a copy of your previously filed returns prepared with online TurboTax https://ttlc.intuit.com/questions/1900748-how-do-i-get-a-copy-of-a-return-i-filed-in-turbotax-online

https://ttlc.intuit.com/questions/1900748-how-do-i-get-a-copy-of-a-return-i-filed-this-year-in-turbo...