Welcome on your trial site,
To show you how much it is easy to modify where to create of piece of news web pages as well as menus,
but also to manage:
- Newsletter
- A catalog or an online shop
- A multilingual site...
Type in the left module of identification " redac " as identifier and password to be directly able to modify articles via the icon 
or in the module of administration to modify, create or manage the various modules.
MAKE OUT A TEST, it is the way the simplest to learn.
If you know just a little the use of a word processor, you know that it is more useful to work with a style sheet css.
Otherwise here is a small explanation: a style sheet allows to apply to all the contents of your documents to be associated with the same theme. If you change theme, a complete set of new colors, polices and effects is applied to your documents.
Thus rather than to write a title in such police, such size and such color Titles, it is simpler to write everything then surlignant the various titles, their apply their style:
Title type1,
Title type 2.....
To understand better, modify the theme of the site via the module: choice of the theme.