Thanks for responding. As for using Opera Sync, is there really any point if my computer is the only device I'll be using?

Finding the info in the Opera menu raises a mystery. For the cache it gives me: /Users/robertford/Library/Caches/com.operasoftware.Opera
There's a problem. It shows a library folder in my user folder. There is no library folder in my user folder.
If I click on the icon for my computer, I see four folders: Applications Library System Users
If I then click on the Users folder, than my folder, all my stuff is there, but no library folder.
If I go to the Library folder outside my User folder, and go to the cache folder, there is nothing for Opera. Only several com.apple files.
The System folder also has a cache folder. Same thing -- just more com.apple files.

So it's been two days now, and not a single response.
I have a new question. Where does one go to get help with opera? Or is it the case that once you download, you are on your own?

I am using opera on a Mac mini (1.4 GHz Intel Core i5) running 10.11.6 (el capitan).
This is the first time I've used opera. I have an updated version I wish to install. However...
I am concerned about whether or not this new version will save my bookmarks. I can't seem to find any information on this question.
I decided to locate and copy the opera bookmarks plist on my computer. To my surprise, I could find nothing for opera in applications support, preferences, or anywhere else I could see.

So I have 2 questions:

Where is the opera bookmarks plist on my computer?
Will the new version of opera save my bookmarks from the old version?