Drupal makes it quite simple to manage the menu for your site.
After logging in, hover over the menu with your mouse and you'll notice a gear icon in the top right corner. Click that, and select the "List links" option.
This opens an administrative interface where you are able to
- re-order links
- nest links under parent links
- edit the text
- disable the link so that it doesn't show in the menu
Delete: This will only delete the link from the menu, it won't delete the page.
If you've changed the text here, that does not change the URL of the associated page. For example, if the link Faculty is changed to Faculty and Staff, the link of the page is still dept.barnard.edu/faculty. If it should match, go to the page and make a new draft, scroll to the bottom and select 'Domain-specific paths', find dept.barnard.edu and change faculty to faculty-staff - do not use capitals or spaces.
If you've moved a link to be under another item, edit that page's Domain-specific path to reflect that move. For example, East-Asian Track used to be a main link, change the path from east-asian-track to major-requirements/east-asian-track.