wordpress-varibles.php

<?php 
//show wordpress site title 
 bloginfo( 'name' ); 
//show wordpress homepage url and support multi language
echo esc_url( home_url( '/' ) );
//page or post title 
the_title();
//show the content of page or post 
the_content(); // should be inside loop
//post thumbnail into src
the_post_thumbnail_url( 'xxx' ); //replace xxx with image size
//show auther name 
the_author();