Problem to create a new DB and user

When I try to create a new DB and user (on ubuntu 16.04), via Wordpress install script inside the program too, EHCP stops with these regardings as you can look at the file attach:
Success sending info to daemon ()
Some Error Occured.
Could not connect as root!

and

Warning: mysqli_connect(): (HY000/1045): Access denied for user 'root'@'localhost' (using password: NO) in /var/www/new/ehcp/classapp.php on line 9047

Can you help me?

Thanks in advance

AttachmentSize
Image icon ehcp.jpg151.83 KB

In your screenshot, there is no:
"access denied for user 'root'@localhost "

but there is,

"access denied for user ''@localhost "
This means, your db root user is set empty, in config.php
Check your config.php in ehcp dir.
it should be root. the user should be root there.