You cannot transfer your complete 2017 tax return into a 2018 tax return. You can only transfer personal data and things like company W-2 information but no actual numbers.
If you used the CD/desktop product for 2017, there is a what if worksheet in the 2017 software that you can use to estimate the 2018 results based on 2017 data. To use the worksheet, open your 2017 tax return and switch to forms mode. Click on Open Form at the top left and type what in the search box. Click on the What If Worksheet. After you open the worksheet, click on copy column 1 to column 2 and then click on the box to use 2018 tax rates.
