According to your message you need to file new 2014, 2017 and 2018 returns? You can't use Turbo Tax to file 2014.
FOR 2016, 2017, 2018
How to prepare a prior year return
https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-prepare-a-prior-year-tax-return/00/25...
You can't do a prior year return online or efile it, but you can buy either the cd or download the desktop versions for the last 3 years from Turbo Tax here....
http://turbotax.intuit.com/personal-taxes/past-years-products.jsp
Or you can check for Turbo Tax for all years on Ebay or Amazon, etc.
Either way you will have to mail in your return. And if you are doing more than 1 year, send each year in a separate envelope. Sometimes the IRS will just staple all the sheets together and miss a second return.
