a2ensite is a nice command that creates the symlink needed for an apache config file from sites-available to sites-enabled.
Nginx doesn’t have such a command, but it is quite simple to create the symlink through bash.
Just run this command:
sudo ln -s /etc/nginx/sites-available/mysite.com /etc/nginx/sites-enabled/
And reload nginx config
sudo service nginx reload
If you want to turn the site off, just remove the symlink.
sudo rm /etc/sites-enabled/mysite.com
That will keep the config file in sites-available so you can turn it on again if need be.