I want to start my taxes over but it won't let me. Help!!

If you haven't filed, registered or paid you can try to clear and start over

https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-clear-and-start-over-in-turbotax-online/00/26444

Or if it doesn't let you clear and you haven't paid or  filed you could just start a new account.  Online is only good for 1 return per account.  But you can use the same email address for 5 accounts.   How to start another return in the Online version

https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-start-another-return-in-turbotax-online/00/25596

If you haven't submitted your taxes, go to the drop down tabs and just correct what need to be corrected. If you can't do it that way before you submit it you will have that option. Only thing is if you have submitted your taxes you will have to reach out to an expert tax handler through TurboTax and see if they can help or do an amended return. Hope I was able to help 😊.