Since you have just activated the
Free Trial for your Google Cloud project, it will take some time for your credit card to be verified for your billing account to be opened. As of the 12th I am seeing your Billing Account is now active, and so I ask that you attempt to re-create your Compute Engine instance again.
I also recommend you enable the
Compute Engine API if it is not already enabled, which may be required by the API you are using for programmatic access and control over your Compute Engine instances.
If you are still seeing issues with Billing after performing the above, you may contact our
free billing support and they will be able to investigate the issue further for you. Just ensure you provide your Billing ID and Project ID found in the
console for your project.