$content = get_the_content();
preg_match_all('/<h2>(.*?)<\/h2>/', $content, $matches);
$tags = $matches[1];

$content = get_the_content();
$stripped_content = wp_strip_all_tags($content);

$content = get_the_content();
$dom = new DOMDocument();
$dom->loadHTML($content);
$links = $dom->getElementsByTagName('a');
$tags = [];
foreach ($links as $link) {
    $tags[] = $dom->saveHTML($link);
}

$content = get_the_content();
$tags = [];
$doc = new DOMDocument();
$doc->loadHTML($content);
$images = $doc->getElementsByTagName('img');
foreach ($images as $image) {
    $tags[] = $doc->saveHTML($image);
}