Learning WordPress - Any advice or resources

Is the site built on a classic theme or a block theme?

In my limited experience, the devil in the detail is associated with the theme that it's using.

Hateful hateful stuff - although must be good because it powers a good chunk of all websites.

Wordpress is fine.
Many of the themes or plugins however....I would put effort into understanding what these are.

A specific query is that it keeps asking me to update the version of WordPress I’m running. If this was a phone software update I’d do it without hesitation, but I’m concerned it’s a slightly bigger and riskier deal with a website.

Go into the wp-admin panel. There will be a link that says "update." Click it.

All other things aside, the "one-click install" is something which WP prides itself on. The only gotcha I can think of is if they're running custom code, and if they're saying "we don't know how to upgrade it" then that would seem unlikely.

Thanks @cougar. It's asking me about backups, I'm not sure I have on or know how to make on. Is it too much of a risk to do an upgrade without one?

It's rare that a Wp core database or plug-in update will break a site but I have had it happen once or twice. It's usually because of an old unmaintained plug-in or custom code in the theme.

Make a note of the version of WP you are upgrading from - worst case scenario is that you might have to download that version and overwrite the updated version.

Do you have SSH or ftp access to the hosting? Or access to the control panel of the hosting?

Thanks @cougar. It’s asking me about backups, I’m not sure I have on or know how to make on. Is it too much of a risk to do an upgrade without one?

Always a good idea to have one. I host our club website on Google Cloud and have scheduled backups automated every week, just in case something goes catastrophically wrong!

I still like books for these sorts of things.  I tend to go to amazon because it lets you read a chapter of a lot of books and that way you can find one that talks in a language you understand and is pitched at the right level for you.  I then usually try and buy it elsewhere if I can.  In your case if you haven't done it before then a basic one that had a chapter on updates is likely to be ideal.  I've never found youtube great for this sort of thing although for occasional very specific stuff it's good.  Books seem often to have more thought put into them so that they are consistent for their audience

If you have access to LinkedIn Learning there's 80 WP courses just searching for WordPress.