Hi Arthur,
Multiple languages has nothing to do with SP Page Builder. You need to set up the Joomla 4 correctly so it has support for the languages you want to use, activate the language switcher with appropriate flags, build the menu system for the languages that should be activate and finally build the pages in SP Page Builder. If you have two (2) languages, build the the source language page first and associate that page with that language, then make a copy of that page and associate the copy with the next language to use and off course change the content on that page.
It is best to build all the pages first, and then associate them to the correct menu item, that will speed up the development process rapidly.
You could alway manipulate the SP Page Builder pages directly in the database with manual TSQL commands or write a procedure that do what you want to achieve, but then you should be familiar with SQL scripting and make sure that you alway have proper backup before you proceeed.
Hope this helps you on the way