For aggregate info use "Get-NcAggr"
Example:
Connect-NcController {ipaddress}
Get-NcAggr
$aggr = Get-NcAggr -Name {aggregate name in list}
$aggr | format-list
...if you need more detailed info then drill into any of the 'DataONTAP.C.Types' objects you see listed...
$aggr.AggrSpaceAttributes
...to reference specific properties use $aggr.{propertyname} to retrieve the value
$aggr.AggregateName
$aggr.AggregateTotalSize
$aggr.AggregateUsed
$aggr.AggregateAvailable
$aggr.AggrSpaceAttributes.PhysicalUsedPercent
For Volume info use Get-NcVol and for LUNs use Get-NcLun, and do the same drill downs as in the Get-NcAggr example above to find the needed values...and use tab completion when drilling down into the objects - makes it a LOT easier than all that typing 😉