Welcome to the Make community!
Make a copy of all the items in Google Sheets first. For more information, see How to pick an existing post from a wordpress website so it can be automatically shared on SM - #2 by samliew
Hope this helps! Let me know if there are any further questions or issues.
— @samliew
P.S.: Did you know, the concepts of about 70% of questions asked on this forum are already covered in the Make Academy. Investing some effort into it will save you lots of time and frustration using Make later!