Normally, the menu you will be editing is the Main Menu. The Main Menu is the menu structure that the UMN Drupal system uses for what we typically consider our site’s navigation.
Click +Add Link.
Provide a title for the item in the Menu link title field.
Provide the URL for the item in the Path field.
In general, it is best to use Drupal’s internal URLs when linking to pages within your site. A Drupal URL is normally node/ followed by a number (e.g. node/34). To find a page's Drupal URL, you need to be on the page and then click the edit tab. The Drupal URL will display in the browser's address bar.
Fill in any additional optional fields.
Recommended optional fields include: Parent Link. The default is Main Menu, which will place the link in the main navigation. Selecting a parent link will place the newly added link in the submenu of the parent.
Click Save. You should see the new link added to the list of links for the menu.