Try this support document regarding Home Sharing. Learn more about Home Sharing - Apple Support
Basically, all you are going to do is ensure that both computers are authorized with the same Apple ID. Make sure that iTunes is running and one the same network as the other computer you are trying to connect to. Turn on Home Sharing, and indicate the Apple ID you want to use. Open iTunes on the second computer, and you will see another icon in iTunes that will identify the two libraries. The one on your computer you want to share, and the one for that computer. You can go into the shared library and copy songs and paste to your laptop.