I only want to file federal

You can skip filing your State tax return, but your e-filed federal return will need to be accepted before you can e-file your state (or, you can just paper-file your state return later. More info)

Here are two ways to skip your state in TurboTax Online:

1. Delete your state return, file your federal return now, and then come back later re-do your state return; or
2. Pay for both your federal and state returns now, and when you get to the Let's get ready to e-file screen, select the File by mail button and click the I'm not ready to file radio button below your state and click save.

Method 1 doesn't require up-front payment for your state, but you'll have to re-enter your state information. Method 2 saves the work you did on your state return but requires up-front payment.