Can we do three, four, or more way calling? That would be cool.

Yes, you can do conference calls with several people in different
locations on line together.

If you are serious about using Skype, get a headset with a microphone.
You can get them for a few bucks. Listening through the computer
speakers and using a microphone can cause feedback problems for you and
ambient noise problems for the person on the other end.

I have used headsets that plug into the computer's sound input/output
ports, USB headsets, and BlueTooth headsets and they all worked fine
with Skype.