Review how to enable menus on content types.
To create a new menu navigate to /admin/structure/menu. You can create new menus by clicking "+ Add New Menu" or navigate to admin/structure/menu/add.
To make new menu links, simply add a link and configure the link preference settings.
You can also pick which menus are available for each content type. Navigate to the article content type settings at /admin/structure/types/manage/article