Joomla is just one of many free systems to organize your web page design.
Joomla is a free and open source content management system (CMS) for publishing content on the World Wide Web and intranets and a model–view–controller (MVC) Web application framework that can also be used independently.
Joomla is written in PHP, uses object-oriented programming (OOP) techniques and software design patterns[citation needed], stores data in a MySQL database, and includes features such as page caching, RSS feeds, printable versions of pages, news flashes, blogs, polls, search, and support for language internationalization.
...
http://en.wikipedia.org/wiki/Joomla
But you could have found that with a Google search. Do you have any idea of how deep this goes? Do you understand what PHP is? Do you have an idea of what SQL is? Have you unwritten any amount of HTML code? With CSS?
To test your code you will need either a remote server, or else the equivalent on you local system.
Not trying to discourage you or anything like that. Your name indicates this is new stuff for you. But hang on. There are many here who will help you with your goal to learn how to design web pages.
