Hi I just have a question. I tried doing my taxes last year on TurboTax but the results didn’t seem correct to me so I got frustrated and never finished them. I understand there is a deadline in

See this TurboTax support FAQ for completing a 2018 tax return started with the online editions - https://ttlc.intuit.com/community/prior-year-return/help/how-do-i-finish-a-prior-year-return-that-i-started-in-turbotax-online/00/26322

You have three years to file a tax return for a tax refund.  If you did not file an extension for the 2018 tax return then that means you have until April 15, 2022 to file for a tax refund.  If taxes are owed then there is no time limit on when the tax return can be filed.  Penalties and interest continue to accrue until the tax return is filed and the taxes owed are paid.

[Edit]  There are no penalties for filing after the due date if the tax return is being filed for a tax refund or there are no taxes owed.