Menus organize the content : They are containers for pages.

2 menus can't be changed : "Main menu" and "System menu".
The "Main menu" is the basic menu if you only have one menu in your website.
The "System menu" contains system pages, like the 404 page.

Adding one menu

Go into the panel : Content > Manage menus...

Click on the button : Create menu

Display one menu

To display the pages of one menu in views, Ionize comes with 2 tags :

<ion:navigation /> : This tag provides a one level navigation.

<ion:tree_navigation /> : Displays the complete tree of pages.

<!-- Example of the navigation tag usage : -->
<ion:navigation level="0" tag="ul" id="my_nav" class="navigation" active_class="active" />

<!-- Result : -->
<ul id="my_nav" class="navigation">
    <li class="active">Home</li>
    <li>About us</li>

<!-- Example of the tree_navigation tag usage : -->
<ion:tree_navigation tag="ul" id="my_nav" class="navigation" active_class="active" />

<!-- HTML Result : -->
<ul id="my_nav" class="navigation">
    <li class="active">Services</li>
            <li class="active">Webdesign</li>
    <li>About us</li>

Look at the Ionize navigation tag documentation to see complete features of these tags.