To create a menu in WordPress you need:
- a link to a destination content
- a menu name
- a menu location
- pick your menu items and order them
A link to destination content
All menu items allow to access a content on your website, you need first to create those content, they can be posts, pages, products if you’re creating a e-commerce website.

Create a menu name
You can have more than one menu on WordPress, this can be important depending on your template. To create menu name go to the Appearance => menu tab in your admin area.

Below the tab ‘Edit Menus’ you can see a notification to create a menu id needed. WordPress have by default a menu that is created, in this image you can see this menu is named ‘first’ and have 3 items.
By clicking on ‘create a new menu’ you get a new page to do so.

Create a menu location
A menu location, is the place where you want to use your menu, on the page above, we have many choices below the ‘Menu settings’ title, you can see for example that your menu can be allocate to the footer and not only the ‘Desktop Horizontal Menu’ a more frequent location ( below the header ).
Pick your menu items and order them

After having created a menu, you can fill it with menu item. Going back to the appearance=>Menu page, you have ‘the Add menu items’ column to choose from to add you menu. One thing to keep in mind is that all your contents are available in that column, each one sorted by category, Pages, Posts and so on. For example if your have products has content, you will have a category product to choose from.
Last task order your menu, indeed to have you’re items menu in order you can drag and drop them, wordpress is very intuitive, you can also give a name to you menu item, by clicking on it new fields become available.
That’s it you’re menu is ready, you can enjoy it.