How to manage moodle?
I suggest this book as a starting point.
https://www.packtpub.com/hardware-and-creative/moodle-2-administration
Darko's suggestion is a really good starting point, but if you do not want to wait for the book to be delivered, you can always start by the traditionally male method, that is, "what does this button do?" and after playing with it for a few weeks, then read the instructions. Alternatively, you could look at what each aspect of the Site Administration menu does by going to that page and reading the Moodle Docs that are associated with it. There are popups and links that explain each element on each page providing valuable information.
The best option, I found when I started, was to download and install a Xampp Moodle to my standalone desktop (now laptop) and trying to break it. In this I found what I could and couldn't do as opposed to what I shouldn't do. On breaking, I would uninstall/delete everything the Xampp module installed, reboot and reinstall it. I found I could apply what I learned to my production site. Worked for me.
In any case, this is a real adventure, something new that will challenge you and help you develop a whole new range of skills. Good luck and welcome to Moodle!
Ha ha that's how I learn, too. But I'm not male. My mom learns the same way. "What does this do?" <click> "Ooops!" <reinstall>.
I suggest you to join the Moodle team on https://learn.moodle.net/
There are many topics about learning with Moodle for each event.