The Browser by default doesn't load Addon beyond the installed default set with Firefox itself. What your seemingly experiencing looks like malware infections. Popups only come from sites or infected system trying to get you to install malware popups if you didn't use them. So you should use:

FireFox in "Private Mode windows" and find them and remove them and do a computer scan for malware popups. Beyond that would require a computer shop to clean the infection if you can't find and remove it.

First it added something called ublock origin which I did not ask for.

The Firefox web browser from mozilla.org does not come with Extensions like uBlock Origin as it is a third-party extension. https://addons.mozilla.org/firefox/addon/ublock-origin/

https://support.mozilla.org/en-US/kb/cannot-remove-add-on-extension-or-theme

Private mode windows just establishes a private window for that tab, but I can find nothing in Settings which will do so universally. This time when I opened Firefox it automatically installed AdBlock. It now looks like I have both AdBlock and Privacy Badger installed, neither of which I asked for. Firefox is suddenly installing these things automatically, and I do not want ANY of them. This looks more and more like I Firefox bug. I have used Firefox since 2007 and have never had this problem.

If you type or paste about:policies in the address bar and press Enter to load that page, are there any add-on related policies listed on the Active panel? Normally, it just says "The Enterprise Policies service is inactive." so anything else could be an indication that someone has embedded a policy file in your Firefox (or policies in the Windows registry).