The module has its own install script, it will create the required database entries.
Configuration:
Go under Administer section
Go under Site Building -> Modules -> Other and make sure "JSXGraph for Drupal" is enabled.
Go under Site Configuration -> Input Formats click on configure next to "JSXGraph for Drupal"
Make sure the filter is configured to your satisfaction, eg HTML filter is run after JSXGraph filter etc. (I will learn how to improve this part of installation).