If it's your first time with an iPhone, things might be a bit confusing. Here are a few tips to get you started.
Note: A lot of these tips work on iPad too!
You can organize apps into separate folders. Tap and hold an app until it starts to wiggle. Then tap and drag the app on top of another app you'd like to keep in the same folder. Name the folder whatever you want. Tap the home button on your iPhone when you're finished.
Download Google Maps for iPhone and use it instead of Apple's mapping app that comes with your device. It's much better. Just open the App Store and search for "Google Maps."
Sometimes apps will keep running in the background. But that can drain your battery. You can tell apps not to run in the background by tapping Settings > General > Background App Refresh.