Setting up asterisk on a man network

Hello,

I am so so new to this technology!!! lately I found out that there’s no single location in my country that has a MAN(Metropolitan Area Network) network running, so with some friends we want to make a difference by starting our own country’s (Nigeria) first ever MAN open source network.
One of the services we are trying to install on the network is a VOIP service which enable people use free to make VOIP calls.
At the moment I want to know if Asterisk can help me achieve this. if yes, how?

If we eventually get to configure asterisk working on the network, my thinking is we will need an application that connects to the Asterisk PBX on the server to enable two devices on the network communicate, right?