Hi Noé ,
well, your database would typically be on the same server, that is the localhost. If you can access the files for your installation, look in file moodle/config.php and you will see the values for dbtype and dbhost.
The typical setup is:
$CFG->dbtype = 'mysql';
$CFG->dbhost = 'localhost';
$CFG->dbname = 'moodle';
in which case you will find mysql running as a service on your localhost server, and the database moodle within that is the one for you to examine.
If someone else is hosting your moodle for you, then they should be maintaining the database, and can check the above for you.