No, you do not have to have a skype webcam to use skype. In fact, you don't have to have any webcam to use skype. You can make voice calls if you have a microphone, and you can chat regardless....
Getting Skype: There are many different things you can do on Skype. All you need is a Webcam (if not built into your computer already) and the software - which you download from the Skype website....