@Victor_Barbosa It just occurred to me that you might be asking a more simple question than we responders thought.
When you install OpenEMR and open it for the first time you only have one user account, the default ‘admin’ account who has administrative privileges. And you have no patient records unless you create them.
To make the OpenEMR instance more representative of a real clinic you would need to create several user accounts with different ACLs, and a few dummy patient records for people of different ages and medical statuses. Similarly, to test the EMR’s billing capabilities you need to configure the clinic itself and the practice settings.
This forum contains several references and links to demo data which can be generated and imported into OpenEMR.