In order to remove all Azure managed disks that start with the name disk, in your PowerShell session type:

Get-AzDisk -ResourceGroupName yourgroupresource -Name 'disk*' | Remove-AzDisk -Force -Verbose

In order to display the properties of a managed disk, in PowerShell session type:

Get-AzDisk -ResourceGroupName yourresourcegroup -Name yourdiskname

Check disk performance SKU a particular disk is using by typing in your PowerShell session:

(Get-AzDisk -ResourceGroupName yourresourcegroup -DiskName yourdiskname).Sku

It comes helpful to know how to update the size of a newly created disk in Azure. So, in your PowerShell session type:

New-AzDiskUpdateConfig -DiskSizeGB 64 | Update-AzDisk -ResourceGroupName yourresourcegroup -DiskName thenameofyourdisk

Verify:

Get-AzDisk -ResourceGroupName yourresourcegroup -Name thenameofyourdisk