It is selfish and ambitious from APPLE that even with hardware upgrades we can not download OS Mojave or future XOS I like my 2008 Mac Pro and they just are forcing us to buy new macs, very disappointed from them.
Mac Pro, OS X 10.11
Apple can not support MacOS on every computer forever. Your Mac can still do everything it could do when you took it out of the box, and likely a whole lot more that Apple provided through software updates for free. It is only when they stopped doing so that you felt the loss.
Hobbyists have figured out some patches to do some of this, but Apple does not support them. Some features simply are not supported, likely including Wi-Fi.
You will need to do some searching around, and most of the sites that tell how to do this are in English. Newer AMD cards are not supported because the newer driver uses SSE4.2 instruction set which 2008 processor can not run.
Why Mac Pro 2008 can not be upgrade to Mojave OS even if I make hardware upgrades
