What happens to my IE and favorites if I have to download Firefox?

I am taking an on-line class, and the Office Hours “Chat Window” won’t work. I keep getting an “Error on Page” – the students in the class that never have a problem are doing the course through Firefox, and suggested that I download. What happens to my other web browser if I do this? Yeah, I’m not the most PCLiterate, but I do get by. Would I have an icon on my desktop that would be for Firefox, and then I could use that only for going to that on-line course? It’s not anything to do with a pop up blocker, because I’ve even turned it off, and it still doesn’t work. Thanks for your help.