First off, please note that Linux is just the kernel; the entire system is
GNU/Linux. See: https://www.gnu.org/gnu/linux-and-gnu.html
Anyway, I tried some stuff, and found that I was able to get the result you
described by dragging the panel (that's what it's called in GNOME Fallback,
the desktop environment you're using) into another panel. Both panels
disappeared, but they both came back when I restarted. Did you try rebooting
your system? You can do this by pressing the power button on your machine.
Failing that, perhaps you have your panel set to auto-hide. Try moving the
mouse cursor to the four edges of the screen.
If rebooting didn't fix it and you've ruled out auto-hide, you could try
deleting the GNOME config files. They're in your Home directory; press Ctrl-H
to see them. I'm not sure which directory/directories GNOME Fallback's config
files are in, though.
