The Form 1040-SR is the exactly the same as the Form 1040, it just has larger type. If you are age 65 or older the printed federal tax return will be a Form 1040-SR.
The Form 1040/1040-SR is the federal tax return. All the TurboTax online or desktop editions start out with entering the federal tax return.
Go to this TurboTax website for the Free online edition - https://turbotax.intuit.com/personal-taxes/online/free-edition.jsp
