Wordpress and it's plugins and themes will constantly have updates as developers are constantly adding new features or fixes. Unfortunately, there is no easy answer as to what should or should not be updated.
Really the only time a plugin or theme needs to be updated is if there was a security issue that needs fixing. Otherwise, most plugins are safe to stay as they are. Another thing to be careful of is if they are major updates, major changes could have a big impact on how your website functions and could actually cause aspects of your website to break or even display differently.
If you want some more details, here is a useful post about updating aspects of Wordpress. https://woorkup.com/wait-to-update-wordpress-plugins/