You don't have to start by transferring from 2017. You can manually enter any 2017 info it needs as you go along. Just start a new 2018 return and continue without transferring.
If you need to transfer like to get prior depreciation you need to download the .tax2017 file. See if this will help you download the .tax2017 file
https://ttlc.intuit.com/community/prior-year-return/help/how-do-i-finish-a-prior-year-return-that-i-...
