This article provides some help to set up a first database and create a new user on a new installation of XAMPP.

Access phpmyadmin

Browse http://localhost/phpmyadmin

Create a new user with all-privileges and access to % hosts and localhost

In phpmyadmin, create your database

Modify file

Edit /Applications/XAMPP/xamppfiles/phpmyadmin/
Change user and add your password.
Switch AllowNonPassword to false.
Switch compress to true.

Restart Apache Servers

Back to phpmyadmin

Remove all other users privileges.