on ubuntu, how can I check the author, date/time created, information of a .docx file?

Using ExifTool (Recommended)

ExifTool provides comprehensive metadata, including author, creation date, modification time, and last saved by. 

1. Install ExifTool (if not already installed):
   bash

   sudo apt update
   sudo apt install exiftool
   

2. Run the command to view the metadata:
   bash

   exiftool your_document.docx
   

3. To look for specific fields (like Author or Dates) quickly, you can use grep:
   bash

   exiftool your_document.docx | grep -i "Author"
   exiftool your_document.docx | grep -i "Date"