Open your apps drawer and whichever app you want to move to home screen just hold your finger on it and slide it up like you're moving it from the apps drawer to the home screen. The drawer will close automatically and you will see your home screen. Then you can slide the app into the position you want.
To lock your home screen, the setting can probably be found if you hold your finger down on an empty space on your home screen. A menu will pop up.