First please refer to set up ghost on your VPS.
Set up ghost(a fully open source, hackable platform for building and running a modern online publication) on your google compute engine.
After that, you already have a ghost web server with default port http://localhost:2368
All you need to do to create more ghost web server is easy now.
Make an empty folder.
Ghost install a new instance with different port number.
$ghost install --port 2369
Give the minimum information that asked during executing the command.
Then a new web server is created, so easy.
I have set up 3 web server in just about 10 minutes via ghost on an single google compute engine instance.