first time using linux

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."
Debian is where it's at.
I jest. This is pretty much perfect advice.
But yes, Debian nowadays is damn near perfect.

My advice: install it on a second hard drive. You can also install it besides Windows, but that might break after a Windows update.

Linux feels different on bare metal than in a virtual machine. In a VM, it feels sluggish and is more prone to glitches.

Things to do/ my tips:

use it just like you would use a PC normally (surfing, file management, etc.)
If you decide to install it on bare metal, try gaming on it. It is almost as viable as Windows for that, and pretty much all (single player) games work on it, often even better!
Use the package management system. Linux has the best ever! You don't need to install random stuff from the internet, you just go into the software center, search for it and click "install", just like on Android. System- and app-updates are usually at the same place.
Stay on Mint for a while. You made the right choice, it is one of the best distros out there, especially for beginners! See, what you dislike and what you like, and only then jump to another distro. Otherwise, you will reinstall your OS every week.
Don't try to force-install everything you're used on Windows. Some stuff, like MS-Office, isn't just available here. You have to look out for alternatives, in that case, OnlyOffice or LibreOffice for example.

Software recommendations

There isn't that much Linux-exclusive software out there. Most of it is open source, so it usually gets also published on Windows. But here are some I like that are:

KDE Connect is freaking awesome
Everything from the "Gnome circle" is also elegant and simple. It's a collection of "do one job"-apps that are very polished.
Lutris: a game management software, that shows you your library and also offers quick-installations for Windows-games through Proton. A must have for every gamer, it replaces your dozens of launchers.

This is excellent advice, and I want to stress that linux on bare metal will let you see just how much better it is. It'll fly. You really don't get a sense of how much be there is in windows till you run linux on the same hardware.
- Especially Wayland DEs ^((User interfaces, that run on the new rendering engine; the default "look" of Linux Mint can't utilize that yet)) will perform much different on a real install.
  On a VM, the screen tears a lot and it will perform sluggish, while on bare metal, it will be suuuper smooth and also give you (on Gnome ^((one of the two most popular desktop environments)) ) access to the best touchpad gestures out there, even better than MacOS.
KDE connect has a windows version
- Yeah, but it absolutely sucks

If you already kinda like mint, I suggest moving out of a VM for a proper OS install.

Linux in a VM is just that: A VM. It has the same use case as VMs in general. If you want the Linux experience i think you're better off allowing linux to properly talk to your hardware.

What to try depends entirely on what you normally do with tour PC, be it steam, deluge, or libreoffice. Use your mint installation for whatever you usually do with Windows.

It's really about what you want to do with your computer. Try to do something you would normally do on Windows in Linux. If you're already using an open source program to do it on Windows you will very likely find the same program on Linux.

If you want to play games they will likely not work well in a virtual environment.

- Yes, but that won't work in a virtual environment that doesn't have access to the GPU. OP said they were using Virtual Box to trial Linux.

Firefox, kitty terminal, vs code... Etc :)

If you look up "how to make a bookmark" for example, you might find the tutorial for the right browser you're using, or you might find one for chrome/firefox/edge, or you might find a tutorial on a real bookmark.

Narrowing your search to the specific program you're using will get you better results. "how to adjust mouse sensitivity in Linux" will not get you good results. Look up "... In Linux mint" or in your chosen desktop environment. You'll get much better results.

Check out OnlyOffice. It's a fork of LibreOffice that's almost an exact clone of MS Office. It's a fantastic program that should be familiar to anyone coming from Windows.

Since you're just using a VM, you should try out some other distros and then pick one to install on your machine. Linux Mint is great for new users just switching from Windows. I personally find the KDE Plasma DE to be the best replacement for the Windows 10 GUI, so I'd recommend you check out Kubuntu or KDE Neon.

I've been using Pop!OS recently, and it's amazing. Everything works out of the box with no need to tweak anything, and I love the workflow features like autotiling and the launcher. The Pop! Shop is also something I'm appreciating more. It's an excellent place for new users to look for software, and the flatpak support really makes it perfect for me. I've been using flatpaks instead of official repositories as much as I can recently, and it's been a long time since anything I have installed has caused me issues.