Currently Azure Managed creation is not supported from Azure management portal. You need Azure Powershell command to get started with Azure Managed Cache Service.
Install powershell from the link - http://go.microsoft.com/fwlink/p/?linkid=320376&clcid=0x409
Open Powershell for azure.
Type following command to login to subscription
You will be prompted to login. Enter the credentials and proceed.
Then you need to select the azure subscription of your choice. Type following command to select the desired subscription.
You will be prompted to enter the subscription name. Please enter your subscription name. This can be found on portal – settings menu option on left hand pane as shown below -
To create Azure Managed Cache run following command in azure power shell
New-AzureManagedCache -Name YourCacheName -Location "YourLocation"
This will create the cache in your subscription.
This will create cache with Basic edition and default size of 128MB.
Hope this helps.