Presently using Office 21 and also use firefox. What do I do?

I used to use Firefox when teaching and now use Officer for other uses. I wish to use Firefox but do not have Windows 11 on my computer. I tried to watch and take part in on on-line class but not gain access because I had to have Microsoft Google Meet and also Firefox for the broadcast from the University of Wisconsin-Madison Independent On-Line Plato program. I am trying to get access to the course that I am enrolled in, Legacy Of South Chicago's South Side". I am a registered of the Plato program and 74 years old. Please assist me to use Office Edge/Firefox so I can take the course and future Plato classes. I was a social studies and guidance counselor for 30 years before retiring as an educator. My email address is: [redacted] @gmail.com and also use [redacted] @outlook.com. I have two different emails depending where I am taking a class or other events. Thank you for your assistance. If you need my cell number it is: [redacted phone#]. My mailing address is: [redacted address] When I wasd using Firefox before my address was: [redacted address] and I used Windows 11 when I used Firefox. Thank you for your assistance. Sincerely, Mike Hanson /redacted emails, phone# and addresses from public community support forum.