The menu admin page can be found under Structure » Menus
When you go to the page for configuring your menus, you will see a listing of the menus available plus tabs for creating new menus and the settings for the menu.
Sites typically come standard with these menus: Main Menu, Management, Navigation, and User Menu.
Navigation is the menu that shows in the sidebar and has "add content" on it. Read about the Nav menu here.
Main Menu is the menu most often used in the banner area. It used to be called primary link.
Management is the admin menu.
User Menu is the menu with user-related itsems, such as the link to edit your account.
You can edit and add to your menu system from here:
As you can see, you can easily disable or rearrange items for any menu.