Turbo Tax still has a Free Edition for very simple returns. But they are no longer participating in the IRS Free File website. To enter stock sales you will need at least the Premier version.
Start a Turbo Tax return here,
https://turbotax.intuit.com/personal-taxes/online
Or find another free offer at IRS Free File
https://www.irs.gov/filing/free-file-do-your-federal-taxes-for-free
