Log into your Joomla Dashboard
In the top menu, under Content, hover over Article Manager and then click Add New Article
Next to Title, write a Title for your Article
Next to Category, choose the category your article should belong to
Type in the content for your article. As Joomla uses a WYSIWYG editor (what you see is what you get editor), you have access to normal formatting features such as bold and text-align.
To publish your article, click Save in the top menu.