Swipe up from the bottom of your screen.
This 'menu' should show up.
Turn off your volume when you are not using it. Also turn your brightness down to half way.
If you have all the little icons turned on turn them all off. (Other than your wifi.
Now double tap your home button. Your screen should look like this. These apps are running in the background also causing your battery to run out faster.
Flick the apps up. This close them.
Now your screen should look like this. Tap the screen and it will take you back to home screen.