General questions about the Joomla! CMS
You indeed can change the Menu Item's Type to whatever you want, even after they have been created.
If, for instance, you want to change the Blog Section of a Menu link, go to the Control Panel->Menus Menu->[menuname]->Menu Item Manager and edit the Menu Item. Select the Change Type button and choose the new style of Menu Item Type from the available list. Thereafter, alter the Details and Parameters to reconfigure the display for the new selection as you require it.
Joomla! runs on the PHP pre-processor. PHP comes in many flavours, for a lot of operating systems. Beside PHP you will need a Web server. Joomla! is optimized for the Apache Web server, but it can run on different Web servers like Microsoft IIS it just requires additional configuration of PHP and MySQL. Joomla! also depends on a database, for this currently you can only use MySQL.
Many people know from their own experience that it's not easy to install an Apache Web server and it gets harder if you want to add MySQL, PHP and Perl. XAMPP, WAMP, and MAMP are easy to install distributions containing Apache, MySQL, PHP and Perl for the Windows, Mac OSX and Linux operating systems. These packages are for localhost installations on non-public servers only.The FTP Layer allows file operations (such as installing Extensions or updating the main configuration file) without having to make all the folders and files writable. This has been an issue on Linux and other Unix based platforms in respect of file permissions. This makes the site admin's life a lot easier and increases security of the site.
You can check the write status of relevent folders by going to ''Help->System Info" and then in the sub-menu to "Directory Permissions". With the FTP Layer enabled even if all directories are red, Joomla! will operate smoothly.
NOTE: the FTP layer is not required on a Windows host/server.