The third line is giving med the categories and I either want to limit the text for the categories to 3 or 4 categories per posts or exclude one specific category (only the title of the category, I still want the post to be visible)

$html .= '' . mb_strimwidth( get_the_title(), 0, 32, '...' ) . '';
$html .= '' . get_the_tag_list('
 ',', ','
') . '';
$html .= ' ' . get_the_category_list(', ') . '';