I am assuming you would like to export customer data.
The majority of the courses use IBM DB2 as the database/ To export the data you can either use command line tools provide with DB2. However the recommended method would be to install IBM Data Studio (free download) and use the export facility to create a dump of a table. B Using the same tool you can import the data to another system.
The username/password credentials for the main db2 user is db2inst1/password. The marketing username/password is dependent on the course you are referring to.