I just bought a USB wifi adapter (TL-WN823N) for my RPi2 and I can't get it to connect to my network, it can't find wlan0, even though, as I show in the uploaded image, Linux finds said adapter via USB.
The TL-WN823N is not the same as the Tenda W311MI used in the article you linked so a different driver is probably needed.
I googled tl-wn823n raspberry pi and got multiple hits. You may need to combine the answers from multiple sources as you have a Bullseye (Debian 11) based OS which wasn't available when the RPi 2 was current. If you need to compile a driver from source code, you may need to increase the size of the swap file because the RPi 2 has limited memory.
You might try asking in the RPi forums for a recommendation on a WiFi dongle for Raspberry Pi OS Lite (Bullseye) that will have drivers already installed (for your RPi 2).
Have you set the WiFi country? Previously this wasn't necessary(and I see you are using a 2017 tutorial!), but recent versions of the operating system need you to set a WiFi country, else Wifi cannot be turned on. Its a separate thing to other country settings.
No, the Pi will not connect to any WiFi at all until you set a WiFi country. It's a legal requirement - the allowed frequencies are different in different countries. It previously defaulted to "GB" unless you changed it, but those settings are wrong for many other countries, including for the many who live in the US. They can't stop you setting it to the wrong country of course, but until you set it to something, you'll get no WiFi.