You can use the PHP newline characters \n or \r\n to create a new line inside the source code. However, if you want the line breaks to be visible in the browser too, you can use the PHP nl2br() function which inserts HTML line breaks before all newlines in a string.
Use the php constant PHP_EOL to print the correct end of line symbol no matter what system you’re on.
<?php print "Hello There," . PHP_EOL . "Welcome to PHPCodez"; ?>