Did you download the 2018 program? Have you installed it?
How to install Turbo Tax on Windows
https://ttlc.intuit.com/community/refund-status/help/how-do-i-install-the-turbotax-software-for-wind...
How to install on Mac
https://ttlc.intuit.com/community/installing/help/how-do-i-install-the-turbotax-software-for-mac/00/...
Then when you launch it it should start asking to prepare a new return. If it doesn't then go up to File-New tax return
