Right here is avery quick crash course to Joomla and how to get started

Adding your first page and putting a link in the Main menu to it.

1. Open your admin panel by adding administrator to the end of your website name, like this www.yoursite.com/administrator
   
2. Goto Content > All Content Items > New. You could click on Content Items manager on the home page of the admin system, its the same thing.
   
3. Now you should have a page open with "Content Item: New" wrote on it.
   
4. Ok in the "Title" type any name, use "My First Page" as an example. This will be what the page is called, and how you will find the page in your system later on.
   
5. Now type the same in Title Alias (this box is not actually reqired for anything at the moment, but may be used in the future
   
6. Now the section is used for larger sites, if you are going to build a big site with lets says more than 50+ pages, we would worry about this, but at the moment i wouldnt. Just choose News, and it will auto select Latest News in the Category below.
   
7. This is where we add the link, you can skip this bit if you like. On the right hand side, you can click "Link to Menu" next to Meta Info then highlight the "Main Menu" and type "My First Page" where it says "Menu Item Name"
   
8. Now click