Need some hooks to avoid editing core files

Hi , I Need some hooks to avoid editing core files for basically these two points -

1) I need to add class in image -
$course_media = do_shortcode( '[course_media wrapper="figure" list_page="yes"]' );

which is coming from 'class.shortcodes.php' line - 1843 , I am afraid that if I will do updates in this class file then it may overwrite when updating plugin ? Then how can I do changes in this file , Is there there any hook to do so ?

2) I want to add 'category name' column name in courses listing - /wp-admin/admin.php?page=courses here .