If you're asking how to connect to the wifi network, please see How do I connect to the wi-fi network in the library?. (What works in the library will also work throughout the campus.)
If you're asking how to add wi-fi capabilities to your computer, all laptops sold within the last several years should already have a wireless adapter, which is the necessary hardware. If you have a much older laptop, I'd be a bit concerned about whether you're able to run a current operating system that can connect to our wireless network. If you're using Windows, you should be running at least Windows 7 (Windows Vista may work too, but Windows XP will not).