How to fix "undefined variables" error messages

My site was recently migrated from one host to another and a series of error messages have cropped up as a result. Here are the messages I’ve noted along with how the code is written on each line. Please let me know how to adjust. Thanks!

Notice: Undefined variable: target in /home/content/30/11933430/html/wp-content/themes/HighendWP/includes/shortcodes.php on line 3938
$title = ‘‘.$icon.$title.’‘;

Notice: Undefined variable: auto_rotate in /home/content/30/11933430/html/wp-content/themes/HighendWP/includes/shortcodes.php on line 1596
if ( $auto_rotate == “no” )

Notice: Undefined variable: height in /home/content/30/11933430/html/wp-content/themes/HighendWP/includes/shortcodes.php on line 2036
if ( substr($height, -2) == ‘ms’ ){

Notice: Undefined variable: height in /home/content/30/11933430/html/wp-content/themes/HighendWP/includes/shortcodes.php on line 2040
if ( substr($height, -1) == ‘s’ ){

Notice: Undefined variable: animation_delay in /home/content/30/11933430/html/wp-content/plugins/dnd-shortcodes/admin/shortcodes.php on line 1298
return ‘<ul class=”dnd_shortcode_ul ‘.$class.$animation_class.'”‘.$animation_animation.$animation_duration.$animation_delay.’>’.do_shortcode($content).’‘;

Warning: implode() [function.implode]: Invalid arguments passed in /home/content/30/11933430/html/wp-content/themes/HighendWP/page-blog-fullwidth.php on line 34
$cats = implode(‘+’, $cats);

Notice: Undefined variable: hb_social_n in/home/content/30/11933430/html/wp-content/themes/HighendWP/includes/widgets/widget-social-icons.php on line 73
} else if ( $hb_social_n == ‘vkontakte’ ){