TurboTax does not offer any free tax programs for tax years prior to 2020.
To complete and file a 2019 or 2018 tax return using TurboTax you would need to purchase, download and install on a personal computer one of the 2019 or 2018 desktop editions from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/
A 2019 or 2018 tax return can only be printed and mailed, it cannot be e-filed.
If you want to file for free you can fill out the forms by hand. Here are some basic forms.....
Here is the 2019 1040 return
or if you want bigger type use 1040SR for Seniors,
2019 Instructions https://www.irs.gov/pub/irs-prior/i1040gi--2019.pdf
2019 EIC and Tax Tables https://www.irs.gov/pub/irs-prior/i1040tt--2019.pdf
2019 Schedules 1-3
Don’t forget your state. And you will have to print and mail your returns. So be sure to attach copies of your W2s and any 1099s that have withholding on them. You have to mail federal and state in separate envelopes because they go to different places. Get a tracking number from the post office when you mail them for proof of filing.
Here is the IRS 2018 Form 1040
And instructions https://www.irs.gov/pub/irs-prior/i1040gi--2018.pdf
2018 Tax and EIC Tables https://www.irs.gov/pub/irs-prior/i1040tt--2018.pdf
IRS 2018 Schedules 1 thru 6 (only if needed)
In many communities the senior citizens groups will help low income people by doing free tax returns for them. Check you senior citizen groups in your area and see if they do that where you live.