apt install apache2 php libapache2-mod-php php-pdo-sqlite
 
# Enable/disable modules (/etc/apache2/mods-avaialable/)
a2enmod userdir
a2dismod userdir
 
# Enable/disable sites (/etc/apache2/sites-available/)
a2ensite mysite
a2dissite mysite

The user is www-data and the default webroot is /var/www/html/ (Debian).