From the basic post page you can create any category.
1. Click New Category
2. Type the name of your category and hit enter.
1. Click the arrow by categories.
2. This is what you will see after you click the arrow.
3. Click View all to see all categories.
4. Check the boxes by the categories that you want to add to the menu.
5. Click add to menu.
The category will move to the bottom of the menu and you can click and drag it anywhere in the menu structure. Click here to learn more about menus.