First-time user encounters various problems with Zorin OS

[Aravisian]

@Viktors

Firstly, there is a very weird issue with my keyboard as it often glitches out and keeps repeating some keystrokes like backspace and other letters, but this is 100% not an issue with the keyboard itself as in Windows it works perfectly. A temporary workaround that I found was to disable key-holding whatsoever so that a keystroke cannot repeat, but this comes with a downside – I myself can’t hold buttons on my keyboard for them to be repeated.

You might try:

sudo apt install xserver-xorg-input-all

And try using those device drivers rather than the libinput.

@Viktors

When trying to remove a drive letter from it in Windows so that it is no longer in the UI when browsing my PC, the system app that is used for it, Disk Management, simply has all the options grayed out. Is there a possibility that I can hide it somehow else?

There really isn't, just as you cannot necessarily hide many other aspects of the system. If you are not actively using that drive letter, you can safely ignore it.

The wifi and wifi-usb questions blend together... so, I think a general answer that can be detailed more later may suit.
I think you are likely quite correct that the kernel may be involved. Using DKMS (Dynamic Kernel Module Support), many drivers can be utilized without needing to reinstall them everytime the kernel upgrades.
While that issue causes consternation with some, it is easy to remember that Windows would have the exact same problem if it upgraded its kernels as swiftly as Linux does. In this case, Linux moves faster.
Install git (always useful)

sudo apt install git build-essential

Use git to grab the drivers

git clone https://github.com/morrownr/8814au.git
cd 8814au

Change Directory into that folder

cd 8814au

And then run the installer script with:

sudo ./install-driver.sh

For DKMS Support, instead:

make dkms_install

Not all drivers work with DKMS, however. So the most System Stable move is to install an LTS stable kernel and default boot to only that kernel.
For example, you might use the 5.8 kernel:

sudo apt install linux-headers-5.8.0-63-generic linux-modules-5.8.0-63-generic linux-modules-extra-5.8.0-63-generic linux-image-5.8.0-63-generic

As long as everything works, you would not need to upgrade the kernel as that really mostly applies to providing support for the Newest Hardware.
Lock in the 5.8 kernel as your default boot:

[HOW TO] set an older kernel to default boot

You may need to use an earlier kernel than the current kernel used by Zorin. This method allows you to set the kernel that you will boot into by default. To set the new kernel to default: Boot into the kernel you wish to be Saved. Open terminal and run: sudo nano /etc/default/grub Change GRUB_DEFAULT=0 to GRUB_DEFAULT=saved Hit enter to drop down a line. Add GRUB_SAVEDEFAULT=true ctrl+x to exit, then the y key to say yes to save, then the enter key to save as current configuration. Ru…

@Viktors

Thirdly, is there a way to set a ‘default’ audio device as I have multiple but use only one. Maybe there is a way to just disable the others?

I will let those far better than I am at Sound Issues field this as I am opinionated.
Welcome to the forum.