How do I list category name?
An ElementCriteriaModel is "used to fetch elements with a given set of parameters." {{ entry.blogCategory }} hasn't yet fetched your category element.

You need:

&lt;p class="category"&gt;{{ entry.blogCategory.first }}&lt;/p&gt;


if you are positive there is exactly one of them, or more generally:

{% for c in entry.blogCategory %}
  &lt;p class="category"&gt;{{ c }}&lt;/p&gt;
{% endfor %}