Since it rejected it was never filed. And if you didn't pay any fees (for the Free Edition) if you really want to start over you can abandon this account and return and start over in a new account or even go somewhere else.
Online is only good for one return per account. But you can use the same email address for 5 accounts. How to start a new online return
https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-start-another-return-in-turbotax-onli...
