Fast guide to install dxvk:
1) Go here:
https://github.com/doitsujin/dxvk/releases
2) Download the latest version. In the section that says "Version x.x.x (Latest)", scroll to the end, and where it says "Assets", download the file called "dxvk-x.x.x.tar.gz".
3) Open the file. If you can't, download an application like 7-Zip first. But I think recent versions of Windows do not require external applications to open .tar.gz files.
4) Inside the file, navigate to the "x32" folder. Take the "d3d9.dll" file and copy it to the WoW folder. The "d3d9.dll" file should be in the root of the WoW client folder alongside Wow.exe.
5) Done.