How can I redue my 2019 tax return

As long as you haven't submitted payment, deducted the TurboTax fee from your refund, or registered, you can erase your return and start from scratch in TurboTax Online.

1. Sign in and select a topic to continue your return.
2. On the next screen, from the left-side menu, select Tax Tools, and then Clear & Start Over (select the menu icon in the upper-left corner if you don't see this menu).
3. Answer Yes in the pop-up to confirm.

If you have already filed and it was accepted, you must file an Amended income tax return.  

I need to start all over because IRS reject because I enter the wrong number

so I need to start from the begining ,

You won't be able to clear and start over because you have already filed. However you can fix the return by following the instructions on the email we sent you. Please see this TurboTax FAQ: https://ttlc.intuit.com/community/rejections/help/how-do-i-fix-a-rejected-return/00/26136