I was given a used 2007 Toshiba Satellite laptop with built in WiFi.?

I'm at the library, which is a WiFi HotSpot, and my laptop will not connect to the internet. The librarian will not help and says it must be my settings. If I have built in WiFi, I don't need to buy a wireless internet interface card or something, do I. Needless to say, I don't know what I'm doing.