To update to the latest version, go to the Apple menu and choose Software Update to see if there’s an update available.
Choose System Preferences from the Apple menu on your Mac. Click iCloud, enter your Apple ID, and select the services you’d like to enable.
Want to use a different Apple ID for iTunes?
Click the Option button next to Photos, and select iCloud Photo Library, My Photo Stream and iCloud Photo Sharing.
To enable automatic downloads for your music and apps, open iTunes and choose Preferences. Then click Downloads and select Music, Movies, TV Shows, and Apps.*