How do you plug in webcame on laptop?

Almost all web-cams these days come with a USB plug. Simply find a vacant USB port and 'plug & go' ! If your laptop already as a built-in web-cam, you might have to switch between the two - For example, I use Paltalk and sometimes I need to use an external web-cam instead of the built-in one - Paltalk gives me the option to switch between the two cameras.