Moved to Support. Please post in the correct section next time.
You need to create a child theme:
http://docs.graphene-theme.com/Customisation_using_a_child_theme
Quote:
The sidebar is removed…I don’t know why?????
You need to understand both PHP and how the theme puts pages together. Without that, you probably won’t be able to figure this out. Start with a child theme, and then let us know what kind of modifications you are trying to do.