If you haven’t done so already. install iTunes on your main computer, and set up an iTunes account. Visit www.apple.com/itunes and follow all instructions.
iTunes is really misnamed—it does a lot more than music. It is responsible for keeping your mobile software up-to-date, backing up your iPhone/iPad/iTouch data to your computer, and installing all other iPhone/iPad/iTouch apps. Save your iTunes password in your LastPass account for easy access.
Syncing to Your Desktop or Laptop
Follow these instructions to sync or back up your iPhone data, apps, and media to your desktop or laptop: https://support.apple.com/kb/ht1386.