I want to learn php language for creating a site . And also web designing for creating a successfull site like fb suggest me any class free of cost or any site which would give me full knowlegde of programming and php langauge to create site need. Thankyou
Learning PHP is not so difficult, You can use online tutor like Codeacademy https://www.codecademy.com/learn/php, For best video tutor you can refer TeamTreeHouse.com https://teamtreehouse.com/library/topic:php
You can start learning the php from w3schools. Link:Php
After completing this, you can find projects by searching on google and start practicing on them. Here is a list of php projects: Php Projects
First try to do simple tasks
If you search in google login coding for php, you can get the code easily. try to understand each line of coding. This will give you lot of experience to do the project.
http://www.sololearn.com/Courses/ is another one to learn php. I believe they offer Video tutorials with questions. Good luck learning PHP :D
To create a website like facebook, you need to have much more then just knowledge of PHP. You need to understand many technologies and protocols.
As others pointed, you can start from w3schools with basic PHP and MySQL tutorials. Later you can go on various algorithms and data structures tutorial from google search. When you think you are ready to solve a specific problem, go to HackerRank. They got very nice excercises, its very nice site for learning.
So, when you learn a basic front-end and back-end, you are ready for javascript. Javascript is a language creditable for powerful apps we got in browsers these days.
Be ready for years of working.