A desktop publishing application from Microsoft that focuses on page layout and graphic design.
If you need this done in a hurry, I suggest hiring a professional technician to do the work. Otherwise you'll need to start your research from the very beginning.
Here is a prompt you can use with the AI of your preference. (I like ChatGPT.) You'll likely need some back and forth with the AI to get all the information you want.
Remember that when 'talking' to AI, the more clearly you express yourself and the more detail you include, the better the answer you'll get, which is the same as when you are speaking to an actual person.
If I had more specific information about the contents of your .pub files I could have done better, but this is a beginning:
I have (hundreds, thousands) of Microsoft Publisher .pub files that I cannot open, now that Microsoft has retired Publisher. Many of these files contain (include a few specific features that you clearly describe). These files were originally created in (version of Publisher). What are some of my choices to make these files usable for (explain how you will use the converted files).