Not sure if there are any great resources online but there isn't that much you need to know. I'd say just download it and mess around. Here's some random tips:
Windows has its own terminal package manager called winget, it's very useful.
Nobody uses CMD anymore, everyone moved onto Powershell. The new windows terminal is also nice.
Windows has a lot of random features and controls hidden in its registry, which you can access via regedit. You usually don't want to mess around with it but sometimes it is useful.
There are a lot of scripts online to de-bloat windows and quickly default to the best privacy settings. I'd run that if you're setting up a new install. Note that some of it comes back every time you update and you'll need to run the script again.
Just understand the file system well and how to use the control panel and firewall and you'll already be ready to go as a sysadmin
I've been using https://github.com/hellzerg/optimizer for debloating my Windows VM (Yeah I forgot to mention I have one installed which I use for some school related activities, mostly Office 365 stuff), but a script would definitely streamline the debloating process.
Winget seems interesting, going to check that out!
Powershell, while it seems like a useful tool, is just gibberish to me. Somehow the syntax is just so weird for my brain to wrap around (this is no criticism towards Powershell, more like "I'm too stupid to understand PS")
I do like Control Panel, as it reminds me of the sweet sweet XP times. And I've fiddled around the registry a couple of times, always blindly trusting what some random blog post advices while having no idea what I'm actually doing. It's kinda daunting, but I guess that's just the way it is. Maybe it gets easier over time :D
Oh and one last thing, you may want to install PowerToys. It's an official program that has a suite of features for power users, things like bulk renaming, easier access to environment variables, checking which files are in use by which apps, and a couple of other neat stuff. I use the color picker all the time.