To file a 2018 tax return you will need the 2018 W-2 and any other 2018 tax form 1099 that you received. You should be able to get a cop of a W-2 from your employer and any Form 1099's from the issuer.
To complete and file a 2018 tax return using TurboTax you will need to purchase, download and install on a personal computer, Win or Mac, one of the 2018 desktop editions from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/
A 2018 tax return has to be printed and mailed, it cannot be e-filed.