@natoulie: Updating plugin and WordPress core is completely fine and nothing to do with the content. Also updating theme is fine if you have customize the theme in right way. This means, if you have customize the theme using Theme Options, Custom CSS and Settings then updating theme will not change anything. But if you have customized and core theme files such as style.css, functions.php, index.php and so on. Then updating the theme will revert these files into original core theme files and you will loose your edits. So, if you want to edit functions and files then you need to build child theme and edit it.
So, when I look at your site. I don’t think you have edited any core theme file. In this case you can just update it. Sorry we don’t have videos, you can search in Youtube.com there are lots.