Thanks! I think I got it.
I had fun adding stuff from users and I reached the point where I'd like to display some other things like statistics from the board (total members, total number of posts, blogs etc.). I mean can anyone point me what I'm missing when I place
{number="$stats['total_topics']" format="short"}
in files I've found this
$stats['total_posts'] = \IPS\Db::i()->select( "COUNT(*)", 'forums_posts', array( 'queued = ?', 0 ) )->first();
and I get nothing. I checked out forumStatistics widget code and it has nothing else to it. I bet I'm missing something..