How can I change my form to W-1040

 It is not clear what you are trying to do.    What exactly are you trying to change?    You moved to the U.S. in August of 2019?   And you want to say that on your 2019 Form 1040?  We cannot be sure yet from what you have told us if you should even be using TurboTax.  Depending on your immigration status you might need to use a different software program.  Before you go further with a tax return you need to determine if you can use TurboTax or if you should be using the partner software--sprintax.

NON RESIDENT ALIEN 

If you are a non-resident alien, your return must be filed on Form 1040NR, which cannot be prepared using TurboTax.  You can use TT’s partner, sprintax:

https://www.sprintax.com/non-resident-alien-tax-1040nr-turbotax.html