Create directory

sudo mkdir -p /var/www/newdomain.com/

Permissions

sudo chmod -R 755 /var/www/newdomain.com

Create apache2 conf file for the new domain

sudo cp /etc/apache2/sites-available/000-default.conf /etc/apache2/sites-available/newdomain.com.conf
sudo cp /etc/apache2/sites-available/rampatra.com-le-ssl.conf /etc/apache2/sites-available/newdomain.com-le-ssl.conf

Enable new site

sudo a2ensite newdomain.com.conf

Restart server to make changes to take effect

sudo service apache2 restart