Exhaustive details on your compute engine virtual machine are needed. The instructions require an instance that has Windows Server 2016, Microsoft IIS,
ASP.NET, and SQL Express pre-installed. What are the characteristics of the virtual machine you deployed? Is this instance running? Have you not omitted any step indicated in the tutorial? It would help a lot if you list exactly, step by step, what you undertook prior to the attempt to deploy your app.
The documented instructions guide you by the deployment of your the application to your Windows instance. These ask for right clicking your application in the Visual Studio Solution Explorer pane. A few screen captures of what you see when you then click on "publish to Google cloud" would come handy.