MYSQL showing access denied for use '"@ localhost' when trying to create a new database
1. Try to login Login with any valid mysql user credentials.

If the root user of MySQL doesn't have a password (which is a bad pratice) ensure to set below in config.inc.php file (for eg path: /etc/phpMyAdmin/config.inc.php)

$cfg['Servers'][$i]['AllowNoPassword'] = True;


2.You can also create a new mysql user using below.

CREATE USER 'new_user'@'localhost' IDENTIFIED BY 'new_password';

GRANT ALL privileges ON my_db.* TO 'new_user'@'localhost'; IDENTIFIED BY 'new_password';

flush privileges;