In order to access your prior years' returns, you would need to upgrade your account to Plus. Once your account has been upgraded, you will see all of your previous returns filed with TurboTax and you will be able to download and print them out if needed. The following TurboTax FAQ explains how to do so.
If after upgrading your account you are still unable to see your prior year returns, you may have another account with TurboTax. You can use this link https://myturbotax.intuit.com/account-recovery/ to recover your account with your phone number. If that doesn't work there is a small blue link at the bottom that says Try something else and if you click on that you can locate your account by using your SSN, name, and birthdate.
If you still can't access your account, you can contact TurboTax Support for assistance by following this link https://ttlc.intuit.com/replies/3300041