I opened TT to continue working on my 2021 tax return and there is nowhere on site to "continue". It wants me to start again. Where is my information?

If you haven't efiled or mailed your return or it rejected you can go back in to finish and change anything you want.  Do not click on Amend!

Click on Add a State to let you back into your return.

From Tax Home (the first screen you see after you sign in), scroll down to Your tax returns & documents. You may have to select Show to open the drop down.

Are you in the right account?  It's common to end up with multiple accounts. First LOG OUT of whatever TurboTax account you're logged into right now. Then use this TurboTax account recovery website to get a list of user ID's for an email address. Run the tool against any email addresses you may have used
https://myturbotax.intuit.com/account-recovery/