1. iMessage : You may go to settings => Message => imessage and turn it off
2. Facetime: You may go to settings => Facetime and turn it off
3. iCloud: You may go to settings => iCloud and turn it off
However, do note that different model might have different location to find the iMessage, Facetime and iCloud.
You might need to check with Apple support or their FAQ to find out more.