When you install new apps to your Android, the system stacks up the icons automatically without asking you to select a home screen. But you can subsequently re-arrange the icons on the home screens and on the tray.
Touch and hold any icon on your screen for a second.
Drag the icon to a different spot on the screen, or even to or from the tray, except for the permanent "All Apps" icon.
You can also drag an icon to the left or right edge of the screen until it starts sliding, then drop the icon to another screen.