Getting entries excluding the first
&quot;Measure twice, cut once&quot; goes the saying... (Kind of the opposite here, but the same principle!) - Fetch your data once, then cut it up how you like using Twig filters. In your case you can fetch the first item from an array with [0] and then slice off that same entry from the start of the same array with |slice(1) like this:
{% paginate craft.entries.section('blog').order('postDate desc').limit(13) as entriesOnPage %}

{% set firstEntry = entriesOnPage[0] %}
{% set theRest = entriesOnPage|slice(1) %}

{# ======================================================================= #}

&lt;h1&gt;{{ firstEntry.title }}&lt;/h1&gt;

{% for entry in theRest %}
    {# OUTPUT 12 Entries not including the first #}
    &lt;h2&gt;{{ entry.title }}&lt;/h2&gt;
{% endfor %}