What webserver did you installed? I need more information!!

You probably got the port 80 blocked, check your firewall:

• iptables -L

or if you got ufw

• ufw status

If you want us to help you more you need to give more information:

• Wich one-click install did you use?
• Do you have any error logs in nginx/apache2?
• What kind of application are you running? Have you got the server prerequisites for this app?

A pkg info dump would be nice to see what you got installed, afaik there’s no pre-made images for freebsd with a webserver installed.

What is the content of your /etc/rc.conf?