Hi there and welcome
Skype is a program that lets you speak to other skype users over the internet for free (both via voice and a webcam).
If you purchase Skype credits you can also very cheaply call phones.
As luck would have it, Skype is currently suffering an outage (this is a very rare one) and as such you cannot use it at this moment (they are working on this to be resolved asap).
You can still download it from this link
You just can't use it until they have it resolved (should be only a few hours)
Then once installed, you can register for free an account with them, find any friends that are already on Skype and make free calls.
If you would like any additional information or assistance, please do not hesitate to let me know
Else if you can take a second to rate my service by clicking one of the stars at the top of the screen then submit, that would be greatly appreciated.