Without a doubt, the single most important piece of advice I can give a WordPress blogger is to disable automatic updates to everything, especially the core. When I first started using WordPress I was unaware that it updated automatically and consequently was blindsided when an update caused many of my coveted plugins to stop functioning.
Certainly that experience was a hard lesson to learn, but even harder was learning how to recover from it, which wasn’t very straightforward. In my case, I figured out how to downgrade to the earlier version of the core which entails replacing everything except for the config.php file and the content folder. I won’t go into detail here, but you can look for a step-by-step guide in a later post.
The second best bit of advice I have is to back up your site including the database. I recommend doing so as soon as everything is working smoothly and nothing is broken. That way you can restore the backup in the event an update breaks anything. Details of various backup options will also be provided in a later post though a Google search should prove fruitful.