I'm new to Ubuntu and i just downloaded 13.10. It shows that I have gnome downloaded or at least I think so cause it has a green check by it and an option to uninstall but how do I open gnome?
Log out. Click the Ubuntu logo next to your name, and choose GNOME from the list. If it is not there, you don't have GNOME installed.
Ubuntu uses several parts of GNOME though, so depending on what you're seeing as "GNOME" with the green check in the Software Center, it may not be GNOME as a whole. For example,