I wish to make new custom page in wordpress where I'm able to talk to database and show results. I added one out of root folder. It seems however when I attempt to show menu, headers. It gives error.

Fatal error: Call to undefined function get_header()

Add Template Name: (some name) comment on the top of script, so when you add new page in admin, choose your brand-new template. Also, this PHP script must be in /wp-content/themes/(theme-name)/ folder.

<?php
/*
Template Name: Portfolio
*/
?>
<?php get_header(); ?>

Here:

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