Get Azure AD Users SID's

Powershell

On a computer run the following within PowerShell ISE

Import-Module -Name AzureAD
Connect-AzureAD

function Convert-ObjectIdToSid
{
    param([String] $ObjectId)
     $d=[UInt32[]]::new(4);[Buffer]::BlockCopy([Guid]::Parse($ObjectId).ToByteArray(),0,$d,0,16);"S-1-12-1-$d".Replace(' ','-')
}

Then

Get-AzureADUser | ForEach { [pscustomobject] @{ Name= $_.DisplayName; Sid=Convert-ObjectIdToSid($_.ObjectId)}}

You can do a search within the Get-AzureADUser by using the -SearchString "<USERNAME>"

As the user logged in to a device

Open CMD and type

whoami /user