To setup the Hifiberry Amp2 you'll have to start by removing the driver for the onboard sound.
$ sudo nano /boot/config.txt
To access files on your rpi from your windows machine over the local network you have to install Samba. Samba is the Linux version of the SMB protocol.
One of the first items to setup on a freshly installed Pi is wireless networking. To do so, you have to edit the wpa_supplicant file.
First go to the root environment
$ sudo su