The Line 14 of header.php file is <meta charset="<?php bloginfo( 'charset' ); ?>" /> which is perfectly fine
There is no Error. You can find that the WordPress default Demo is working fine Here: https://wp-themes.com/newspress-lite without any issue
This is not a Theme Issue. You can check activating another Theme like Twenty Seventeen. BTW, what is the PHP Version of your server. If it is not greater than 7 you can request your host to upgrade their host to PHP 7
