I like this office suite. I use it both for my laptop and for my Android phone (as an app).
I use English or Swedish language. I only have access to my phone right now, so it may differ a bit from computer.
This is the way to save a file as a new file. Click:
Tools - file - save as
Explanation (because it might look different in computers):
*Find "Tools" button. (4 squares in a square. The place where you do everything). Click it.
*Find "File" (or something similar, as "Document", that concerns your currently open document) in the tools menu. Click it.
*Choose "Save as". Change the name or file type and save.