The Azure capacity that you get with the $200 free credit is not quite sufficient to run the Horizon Cloud service.
Check out the VM requirements to deploy Horizon Cloud on Azure in the Getting Started Guide here - Microsoft Azure Virtual Machine Requirements for a Horizon Cloud Node
please see my answer on your other question What Limits/Quotas do I need for Horizon Cloud Service? as that covers a lot of this issue too.
Specifically you need to increase the default quota and add the use of F Series VMs, Dv2 and Av2. I *believe* that some of these are not available on the free-trial.
Once you convert the free-trial account to a paid one then Microsoft lets you increase the quotas.
To help with some of the costings there are various blogs and such on the subject. I did write a white paper: RDS Desktop and Application Scalability (https://www.vmware.com/content/dam/digitalmarketing/vmware/en/pdf/products/horizon-cloud-virtual-desktops/vmware_horizon_cloud_service_on_microsoft_azure.pdf ) which does attempt to provide some insights into the operating cost on Microsoft Azure at a production like scale.
hope this helps,