How to add new menus and other modules in Joomla
Menus, as well as other modules, can be added to the frontend of your site through the Module Manager of your admin panel (backend).
Each module can be added to a different position which in itself occupies a specific place on the layout of the page. You can see the different available position and their placement on the frontend if you add ?tp=1 or &tp=1 to the URL address of your site. First, however, make sure that you have enabled the option for module positions preview. To do this go to your backend's Template Manager and click on the Options button in the upper right corner.
To add a new menu to the frontend of the site, first create the menu from the backend's Menu Manager and add the menu items you want it to display. You can also use the panel Batch process the selected menu items to move or copy menu items from other menus to your new menu. To do this, in the Menu Manager go to the menu containing the items you want to move, mark the checkboxes in front of the particular items, then from the Batch process panel at the bottom of the page select the new menu where you want to copy/move the items and click on Process.
After you create the menu you have to make it visible on your frontend. To do this go to the Module Manager, click on the New button, from the window that opens select the Menu module type. Then type a name for the module, click on the Select position button to choose the position where you want it to be displayed. From the Basic Options panel select the menu you created earlier from the Menu Manager. The last thing is to click on Save & Close.
You can add other types of modules from the Module Manager. When you click on New you can see a list of the different module types. For example, modules that display a selection of articles or categories.
Check out the tutorial on adding new menus and modules in Joomla for more information and screenshots.