Limiting Phone Usage

Hello to all, I have been having troubles with finding out how to stop all usage of all in phone apps, safari, face time calls and texting. 

    I am curious how to limit who can call/text/facetime? Also, how to stop the usage of all apps currently downloaded to the phone??

     Any and all help would be greatly appreciated. 

On a side note, How do I accept the terms and policy for the cookies within the T-Mobile website? I cannot log in to my profile on my PC??