Create Resource Groups and Assign Owner Role

createandassigngroups.ps1

$subscriptionId = "<azure subscription id>"
Connect-AzAccount -SubscriptionId $subscriptionId

$users = Import-Csv ./userlist.csv

foreach ($user in $users) {
    $user   
    $g = Get-AzResourceGroup -Name $user.AzureGroup -ErrorVariable notFound -ErrorAction SilentlyContinue
    if ($notFound) {
        $g = New-AzResourceGroup -Name $user.AzureGroup -Location "Central US"
    }

    New-AzRoleAssignment `
      -ResourceGroupName $g.ResourceGroupName `
      -RoleDefinitionName "Owner" `
      -SignInName $user.UserName
}

userlist.csv