The database connection parameters are stored inside .env file (on development environment).
On production environment store it in VirtualHost configuration or .htaccess file. To store variables in .htaccess file VirtualHost must contain the
AllowOverride All directive.
Reading environment variable
$value = env('DB_HOST', '127.0.0.1');
Where first value is the name of the variable, and second is the default value (if env variable is not defined).
Visit http://localhost/phpmyadmin if you are using XAMPP
Source: Laravel Cheat Sheet