Now that your device is up and running, here are a few quick pointers.
Tweak your settings: Most of the underlying system information for your new iPhone--network settings, Mail, sounds, messages, restrictions, wallpaper, and more--is kept in the Settings app. As such, it's a good place to start when you're first getting acquainted with your device.
Set up iTunes sync: If you didn't rUFGestore from an older iOS backup, you won't have any music, video, podcasts, photos, or books on your iPhone. You can remedy that by connecting it with your iTunes library: Just plug your device into your computer via its included USB cable. (Once you've completed this initial sync, you can also set up wireless local syncing; check out our guide for more information.)
Explore the App Store: Your iPhone comes with a bunch of cool built-in apps, but you may want to reach outside the sandbox for more interesting fare. The App Store, which you can access on your device or via iTunes on your computer, features more than 750,000 downloadable apps. To explore the store on your iPhone, tap the blue App Store icon on your home screen. Featured and Charts are both great places to start looking for recommended apps, and you can search the entire App Store by tapping on the Search tab. As the iPhone 5 has different dimensions than previous generations of the iPhone, there may also be a collection in the App Store for apps optimized for your device. (Older apps will still run on the iPhone 5, but they'll do so with black bars at the top and bottom of your screen.)
Talk to Siri: If you chose to set up Siri on your iPhone 5 during the activation process, you're just one Home button press away from having your first conversation. Siri can help you book appointments, find restaurants, look up the weather, talk sports, and occasionally whip out snarky quips about robotic AI. To start, press and hold your Home button; the Siri interface will appear, along with a few suggested phrases to get going.