[SOLVED] Configure Apache2

[Maxxxx]

Hi,
my name is Max and i'm Italian.
excuse-me if my questions are stupid, but i'm newbie to Apache.
2 day ago i installed Apache2 in my home pc with Debian Jessie OS.
I installed it for hobby, not for work, but i'm interested to learn this web server software.
I note that httpd.conf file ther isn't... but i read somewhere in internet taht in new version of Apache this file doesn't exist, and the configuration files are /etc/apache2/apache2.conf, /etc/apache2/ports.conf and /etc/apache2/sites-available/000-default.conf
I left this configuration's files by default and i create a simply file index.html (only for test) in /var/www/html/ directory.
If i enter 127.0.0.1 on a browser of the same pc it work fine, but i don't know how to connect to another pc trough internet.
i check my public ip address, and if i try with this public IP i get error message.

In ports.conf file there is "Listen 80", and apache2 service is started.

Where am i wrong?

Thanks a lot for your attention

[Maxxxx]

I solved...
the problem was my router's firewall... it have no setting options, it is only active or disactive.
I disactivated it and create a port forwarding...
now i'm able to connect to my file.html by my public IP from an external PC or smartphone.

[Maxxxx]

How can i change the title to [SOLVED]?