If your sites theme happens to have a tag block that you don’t want shown, you can simply remove it by removing the following block of code in the theme:
{% if site.tags %}
<ul class="tags">
{% for tag in site.tags %}
<li><a href="/tag/{{ tag.name }}">#{{ tag.name }}</a></li>
{% endfor %}
</ul>
{% endif %}
If you’re trying to remove a tag block from a post page, follow the same instructions except you’ll want to remove the block of code beginning with {% if post.tags %} instead.