Sorry, no. Only the TurboTax online editions for 2019 have the Free edition.
To complete and file a 2018 tax return using TurboTax you will need to purchase, download and install on a personal computer one of the 2018 desktop editions from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/
A 2018 tax return can only be printed and mailed, it cannot be e-filed.