Bubai

use this css to change […] color

.entry-content p a {
    color: black;
}

for hover

.entry-content p a:hover {
    color: black;
}

do it by css or remove entire row html

by css use
.div_name{display:none}

go to editor of the theme from dashboard and open header.php and look line no.34 here you can see this

<?php if ( is_front_page() && is_home() ) : ?>
						<h1 class="site-title"><a href="<?php echo esc_url( home_url( '/' ) ); ?>" rel="home"><?php bloginfo( 'name' ); ?></a></h1>
					<?php else : ?>
						<p class="site-title"><a href="<?php echo esc_url( home_url( '/' ) ); ?>" rel="home"><?php bloginfo( 'name' ); ?></a></p>
					<?php endif;

just replace <?php echo esc_url( home_url( '/' ) ); ?> this area with your external url. example

<?php if ( is_front_page() && is_home() ) : ?>
						<h1 class="site-title"><a href="https://google.com" rel="external_url"><?php bloginfo( 'name' ); ?></a></h1>
					<?php else : ?>
						<p class="site-title"><a href="https://google.com" rel="external_url"><?php bloginfo( 'name' ); ?></a></p>
					<?php endif;

ok so try another one, rename your plugin folder name that is under wp-config folder. then go http://natanamysore.com/wp-admin/

and before that problem what exactly work you have done?

from dashboard go to appearance -> editor -> functions.php from right side , now you can see it’s all code in editor screen

What is your activated theme name?
And first of all make sure your content page or post published then do preview.

just change with it

<form><input onclick=”hisotry.back(-1)” type=”button” value=”<< Return to what you were reading” class=”background”/>

and write this in your css file

.background{background:url(‘your image path here’)}