Hi Iliana.
For the link issue, make sure you've updated the Site record in the
admin. It's under Site > Sites in the admin sidebar. By default it's set
to the local URL, but you should change it to your production domain.
Regarding the tags in blog posts, Mezzanine ships with linked tags in
the default blog post template (blog/blog_post_list.html). If you've
created your own templates, you'll need to replicate that to generate
the tag links:
{% keywords_for blog_post as tags %}
<ul>
{% for tag in tags %}
<li><a href="{% url "blog_post_list_tag" tag.slug %}">{{ tag
}}</a></li>
{% endfor %}
</ul>
See
https://github.com/stephenmcd/mezzanine/blob/master/mezzanine/blog/templates/blog/blog_post_detail.html#L69-L81