To preview your form 1040 using TurboTax Online, you can follow these steps:
In the Desktop version, you can look at the Form 1040 by entering "Forms Mode", or by viewing the PDF through the Print Center.
I don't think I got to fill out the 1040 part to get my second stimulus check. I didn't work last year.
You can file a tax return in 2020 to get your stimulus check, even if you aren't required to otherwise.
When you prepare your tax return for 2020 in TurboTax, you will be prompted to enter how much you received for your stimulus and then the program will calculate the amount of stimulus due you based on your income, number of dependents and payments already received. If any additional stimulus is due you, it will be used to reduce your 2020 income tax liability, and the balance will be refunded to you.
You will see the options when you are done entering your tax information and proceed to the review process.