To see all your apps, touch 
All Apps in the Favourites tray on any Home Screen.
This is where you can see all your apps, including those that come with your phone and those you downloaded on Google Play. You can move app icons to any of your Home Screens.
From All Apps, you can:
Move between screens
Swipe left or right
Open an app
Touch its icon
Place an app icon on a Home Screen
Touch and hold the app icon, slide your finger, and lift your finger to drop the icon into your desired Home Screen
Browse Widgets
Touch the Widgets tab at the top of any All Apps screen
Get more apps
Touch 
Google Play in the list of app icons
To remove an app icon from the Home Screen without removing it permanently from your device, touch & hold it, slide your finger toward the top of the screen, and drop the app over 
Remove.
To view info about an app from an All Apps screen, touch & hold it, slide your finger toward the top of the screen, and drop the app over 
App Info.
TIPS: Some apps can harm you or your device, however, you don’t need to purchase anti-virus software for your phone, Google can verify apps to help prevent harmful software from being installed