As far as I’m concerned, there is only one mandatory plugin you must install on every WordPress site: UpdraftPlus.
This utility runs silently in the background of your site and can be configured to automatically send you an archive of your files, database, and media. You can have it email them to you or – if you have a massive amount of data – it can zip it all and save it to your Dropbox account. There are dozens of other user-friendly options as well:
- You can choose the frequency of your backups.
- You can enable automated email notifications.
- You can choose to encrypt your archives.
- You can have the plugin archive files outside of your WordPress installation.
- You can even have it archive database tables that aren’t related to your WordPress system.
I manage over a dozen WordPress sites and have helped people configure several dozen others and every time I make sure UpdraftPlus is installed. It is breathtakingly simple to use, even if you don’t understand anything about how your site actually works. And having reliable, off-site backups of your website(s) is exactly as important as it is to have them of your local computer. (You are using Backblaze, right?)