Hi zootooyoo, the first step is to download and run the installer, which sets up Firefox. Then when you start up Firefox, it should ask you whether you want to make it your default browser.

If the small "online" installer doesn't work well, you can try the larger "offline" installer from this page (scroll down to your preferred language):

https://www.mozilla.org/firefox/all/

OK, I have absolutely no idea where the installed Firefox went. I thought I was hitting install and I am told the disc could not eject. WHAT? SO, you see I am one of those total morons when it comes to anything computer related. I need kindergarten help

I use Windows, so the details of installing on Mac are not in my muscle memory. But we do have this article:

How to download and install Firefox on Mac

OK, I called Apple, I have Firefox downloaded,,,,,HOWERVER, my options for a search engine are Google, Bing, Yahoo or DuckDuckGo. How do I use Mozilla as a search engine?

This is getting off track now...have you search on how to install firefox?

https://support.mozilla.org/en-US/kb/custom-installation-firefox-on-windows

https://support.mozilla.org/en-US/kb/make-firefox-your-default-browser

Mozilla Firefox or Firefox. For short is a web browser as the company Mozilla does not have a search engine service of their own.

Just pick one of those search engines or another one as there are a lot of options at https://mycroftproject.com/

WestEnd said

This is getting off track now...have you search on how to install firefox?

The OP has already installed Firefox on Mac OSX, the OP just did not realize Firefox is a web browser and not a search engine.