If you don’t have knowledge,  HTML, CSS.

First Go For :  https://www.w3schools.com  Understand learn HTML, CSS.

A PHP file normally contains HTML tags, and various PHP scripting code.

The PHP script is executed on the server, and the simple HTML result is sent front to the browser.

A PHP script can be located everyplace in the page.

A PHP script begin with   and ends with  ?>

PHP statements are terminated by semicolon (;).

The default file extension for PHP files is ".php".

Use for Php sentence in

welcome

<?php

echo "Hello Everyone!";
?>

 

Output : Hello Everyone!

Define PHP variable & rule

•   A variable starts with the ' $'  sign, followed by the name of the variable (example $x;).
•   A variable name must create with a letter or the underscore structure
•   A variable name cannot begin with a number
•  A variable name can only hold alpha-numeric lettering and underscores (A-Z,  a-z,  0-9, and _ )
•  Variable names are case sensitive and  $a and $A are two different variables.

variable Type

1.Local variables   2.Global variables    3.Static variables

  $a=5; // variable
  $B=8;  // variable
          

 $R=$a+$B; //Sum of 5+8

echo “Sum of” .$a. ”+” .$B.”=”.$R;

?>

Output : Sum of  5+8=13