To show post related  tags with links in your single post use this simple code snippet.

<?php the_tags(''); ?>

As we know we can assign multiple tags in a single post if you want to link specific tag use can use below code snippet.

<a href="<?php echo home_url('/tag/tag-slug-name-here') ?>"> Link Name </a>

Get all tags wordpress

If you want to show all tags (without links) used in your whole WordPress site, you can use the below code.

<?php 
$tags = get_tags();
$html = '<div class="post_tags">';
foreach ( $tags as $tag ) {
    $tag_link = get_tag_link( $tag->term_id );

    $html .= "<a href='{$tag_link}' title='{$tag->name} Tag' class='{$tag->slug}'>";
    $html .= "{$tag->name}</a>";
}
$html .= '</div>';
echo $html;
?>

If you want to show all tags (with links) used in your whole WordPress site, you can use the below code.

<?php
$tags = get_tags();
$html = '<div class="post_tags">';
foreach ( $tags as $tag ) {
    $tag_link = get_tag_link( $tag->term_id );

    $html .= "<a href='{$tag_link}' title='{$tag->name} Tag' class='{$tag->slug}'>";
    $html .= "{$tag->name}</a>";
}
$html .= '</div>';
echo $html;

?>