Every time you update WordPress, it’s a good idea to create backups for testing and to restore from. The nerdy way is fine, but really technical. To steer clear of all the BS, we highly recommend BackupBuddy from iThemes.
Just install the plugin, click “Backup”, download the ZIP it creates. If anything goes sideways, just upload that zip and the little importbuddy wizard and follow the instructions. Then you’re back were you started and no one will be the wiser.
Of course, there are plenty of free or very inexpensive backup plugins available for WordPress (400+ actually). I’d just remind you that you get what you pay for.
Well, there you go. Just install and use a backup plugin or do it manually before you upgrade. Even if you never have to restore from one of your backups, they are better to have and not need than need and not have.
For more details on how to use BackupBuddy, see the support article, “Migrate WordPress to New Hosting.”