An easy way to secure your phone is to enable a lock code to unlock it. Follow these steps to learn how to enable a lock code.
From the home screen, drag the bar up to the edge of the screen.
Tap Settings.
Tap Security.
Tap Screen lock.
Tap PIN.
Enter a lock code.
Tap NEXT.
Re-enter the lock code.
Tap CONFIRM.
Tick an option and tap DONE.
The lock code has been enabled.
Now that you have set a lock code, your phone will show you a lock screen when unlocking your phone.