Pages in Joomla are called "Articles."
To add a page, simply submit an article from the front or back end after logging in. Generally, articles are auto published.
QUICK & EASY TIP:
Login to your site from the front end.
Underneath the "Hi Jane" greeting is a "Submit Article" link.
Click "submit article"
Type your text
If you still don't understand this, then you can view one of the many free tutorials on YouTube.com (keywords: add article Joomla),( or the default installation of Joomla (through Fantastico) is filled with default articles that are also tutorials. There is one there for adding articles.
You may also want to join your local Joomla User Group and attend a meeting. It may be hosted on Meetup.com. These groups are usually listed on Joomla.org.
My Joomla User group has webinars for beginners that anyone around the world can join in on as long as you speak English.
Once you have figured out how to add articles or pages, then you will need to take a step backwards and categorize those articles. See the tutorial below for Cory Webb's How-To on that topic.
P.S. Use the link below for HostGator, a web host with the Fantastico installer for Joomla and a telephone support number, to help you out. I use Host Gator and they are the best and cheapest hosting service with the best free traffic analytical tools. No one else has telephone support, believe me! Many of the techs use Joomla themselves.
Host Gator/Fantastico http://secure.hostgator.com/cgi-bin/affiliates/clickthru.cgi?id=montez709
My Joomla User Group Site: http://www.joomladallas.com
Joomla Video Tutorials: http://www.Youtube.com
Cory Webb's "How to Organize Articles" http://www.howtojoomla.net/200609139/how-tos/content-management/organizing-your-content