using chrome os as client in vmware fusion
The system administration is hard stuff. Don't worry. The best you can do is ask here or even elsewhere -because the problem is about the configuration, not Mac-. Download the iso / img from the official repository. Then create a new virtual machine. Configure the settings as you wish (RAM, disk size) and then when disk image requested, select the downloaded one. If it also asks you what OS are you trying to run, try (because Chrome OS may not be displayed) to select it.

This process is universal. The thing is that since the iso contains the boot and kernel, the virtual machine should at least know which files correspond to each function. It may be impossible to boot it if VMW doesnt recognize them. In that case, if you still wanna run VMW -which would be hardcore- I can just tell you to surf the net. 

The easiest EVER is in that case using parallels. Download a cracked copy or buy it if you are a legal guy &#128521;. 

Hope it helps

Edit: And the link you provided is vanilla, not chrome OS. So thats kind of help to install it, which is fine, but in that case you should also take a look at the docs. Did you download the file for vmw? It should work