When opening up Mozilla Firefox on my computer to get to the internet,
my cousin somehow got a screen that asked her something about
"switching users". Now, instead of my firefox browser with my home
page and all my bookmarks, its actually an old homepage of mine and
none of my bookmarks. When windows opens up, there is only one 'user',
so I have no idea how this browser thing happened or what it means or
how to get it back, since I wasn't here to see it. THANKS!!!

Hello danidoodiver-ga,

There are numerous things that could have happened here and there are
different ways of solving this. The first thing to try is to click on
the Start menu and then click on Run.

Copy and paste the exact information on the next line into the Run command:
C:\Progra~1\Mozill~1\Firefox.exe -profilemanager

Click OK

Try all of the profiles listed there to see if any of them have your
bookmarks etc. Please let me know if this doesn't work and we will try
something else.

All the best,

tisme-ga