I can only speak from experience but from my understanding most people’s knowledge of Linux is derived solely from wanting to do something and then figuring out how to do it, instead of studying a list of “things you must know to use Linux”.
I second this. While I’ve been exposed to Linux quite a while back (Linux Mint, circa mid-2000’s if memory serves me right) and was given a “Linux basics” rundown, I only started daily-driving Linux around late 2019, and by then, my knowledge of Linux pretty much have faded. It still hasn’t prevented me from getting re-familiarized with Linux (Manjaro, then Arch). Of course, some bit of knowledge would help, but a lot of the Linux basics you’d need are already out there if you need it. Just look things up if the need arises.
Also, I find having to learn something I don’t immediately would need to use not very productive, even counterproductive at times since it leads me to having a mindset of “I should already know this, why am I being so stupid?”
So yeah! I second this sentiment of “just use your computer, look things up if you have to, it’s not going to hurt.”
And oh, don’t be afraid to mess with your computer from time to time. If you’re concerned about breaking things, you can install the distro of your choice into an old laptop or something, and use that as a place to “mess things up.”
Edit: I forgot that OP already is using Linux in a virtual box. OP can use that as a laboratory to “mess things up.”