No driver for RealTek WiFi-adapter on LinuxMint installation; need off-line solution for this machine

I bought a new laptop, and my IT guy installed Windows 10 on it. It ran perfectly for one whole month,then updated, and went into "Not an authorized Microsoft Product" mode and locked me out. So I deleted the entire system, and installed Linux Mint. It's perfect except that it cannot detect any wireless signals. * I ran

nmcli d

and it came out with

wlan0 = lo
    wifi = Loopback
    State = unmanaged
    connection = --

* Then I tried

sudo lshw -C network

and it responded with

*-network UNCLAIMED
    description: Network controller
    product: Realtek Semiconductor Co.,Ltd.
    vendor: Realtek Semiconductor Co.,Ltd.
    physical id： 0
    bus info: pci@0000:01:00.0
    version: 00
    width: 64 bits
    clock: 33MHz
    capabilities: pm msi pciexpress cap_list
    configuration: latency=0
    resources: ioport:2000 (size=256) memory: d0600000 - d06fffff

It is my understanding that this tells me that there is hardware installed. That it is made by Realtek. However there isn't any software associated with it. It needs some software drivers to make it work. At least, that is what I think. So I tried to find out what kind of software drivers I could use, and so I searched the internet (on a different computer. Remember this LinuxMint computer has no internet at all. Not even a CAT patch connector) and came up with a number of pages where people had this same problem. In general, every single one of them says use some version of one of these commands:

git clone -b v5.6.4.2 https://github.com/aircrack-ng/rtl8812au.git  cd rtl*
wget -N -t 5 T 10 https://github.com/ubantuForums/wireless-info  && chmod +X wireless-info && ./wireless-info

None of these solutions will work for me simply because I have no internet. I have to get the internet first, then I can download and install the driver. So all these suggestions of using this command, or plugging in a patch cable to access the internet is not working for me. My laptop does not have a female connector for a patch cable. And I need a driver. I think what I need to do is perform these tasks manually without internet access. That is to say, get the file, put it on a USB, then install the file in (for example) the downloads directory and then install it from there. Like this maybe... 1. Get on the internet (on a different computer) and obtain the rtl8812au or rtl8812ce file (I still don't know which one to use.) 2. Put it on a USB. 3. Extract it to the LinuxMint computer and put it into the downloads folder. 4. Then run some command that looks something like this, maybe...

cd downloads
    cd rtl8812au . X . X . X. (whatever the version is)
    make
    sudo make install
    sudo service Network Manager restart

I think. I am not a Linux expert, and I only started learning this week. But It makes sense to me. I have been installing Microsoft windows drivers for decades, so this must be similar.... right? Oh Nooooo! I found websites that hold these drivers... * https://gnab/rtl8812au * https://aircrack-ng/rtl8812au * https://gordboy/rtl8812au * https://tomaspinho/rtl8812ce But, you know, when I get to those websites, oh my goodness! Where are the files? When I read the internet comments they say "go to the pages XXXXX, and get the file, extract the ZIP, and install". Not so easy. Which is which, what are the files? As best I can tell, I am supposed to get the code directly. Compile it myself, make a file, ZIP the file and then try to install. That can't be right, can it? So obviously, I am all frustrated and confused, and probably look like some stupid kid to all you grizzly old coders out there, but it's all new to me. It's all strange to me, and you know, if I could get get over this hurtle, I think that I could really start loving this system... playing with it. doing things. It appeals to me. But first I need to get my wifi enabled. So I need youse guys help in this. I have one computer running Chinese Windows 10 that connects to the internet. I have some USB memory sticks. I have a new laptop with LunixMint ready to run, and I am all winning to make this thing work. So here's what I need to solve this problem: * Instructions that a newbie like myself can understand. * A URL where to get whatever files I need, what to get, how to get it. * Installation instructions. Do you all think that anyone can help me out on this? It would mean a lot to me.