How can I link main menu links to submenu links in Joomla!?

Question

I have main menu with sublinks, so when you click mainmenu link, it should go to default submenu link. For example:

Main menu: Homepage | Information

Information submenu has Contact and Location selections and Contact should be active when Information main menu link is activated.

Answer 1

As I see it, you have two options

1. If your main menu is also your home page, you could make the submenu the default menu.
2. Modify the main menu to be an external link to the submenu on your own site.

Answer 2

Use an alias as your menu type and link to the submenu