tried random inputs for database name etc... without success...
There won't be anything random about it. The username and password will be the exact username and password you created in MySQL and then assigned to your wordpress database. The database name will be the exact name of the database you created for your wordpress installation.
Did you successfully give the database user you created permissions on the wordpress database?
GRANT ALL PRIVILEGES ON your_databasename.* TO your_databaseusername@localhost;