Create New User via PowerShell - powershell

Question

I am working on a script creating a new user via PowerShell with user (creator) input. The input I am looking for is for the first name and last name along with some attributes. I would like the samaccountname and the UPN to be auto created from the input. Not sure if this can be done completely but would like to get some input on my current script. I highlighted firstinital as a placeholder to show what I am trying to accomplish.
new-aduser -givenname($givenname = read-host "Input Firstname") -surname($surname = read-host "Input Lastname") -samAccountName ("***firstinitial***"+"$._surname") -userprincipalname "$._surname+"#domain.com" -path "OUName" -whatif
Alrighty thanks for the help below. I was able to do a few more searches and can up with the following. All looks to work except the distingushed name comes up as a single name instead of a space between the first and last name.
#User info entered
$first = Read-Host "First name"
$last = Read-Host "Last name"
$title = Read-Host "Title"
$location = Read-Host "Location"
$department = Read-Host "Business Practice"
$password = read-host -assecurestring "Password"
#Create new user
$Attributes = #{
Enabled = $true
ChangePasswordAtLogon = $false
UserPrincipalName = $first.split(" ")[0]+$last+"#domain.com"
Name = $first+$last
GivenName = $first
Surname = $last
DisplayName = "$first "+" $last"
Office = $location
Department = $department
Title = $title
samAccountName = $first.split(" ")[0] + $last
AccountPassword = $password
}
New-ADUser #Attributes -whatif

Answer 1

You can add this to get the $_.givenName as the first initial:
$gn = (read-host "Input Firstname")
$sn = (read-host "Input Lastname")
new-aduser -givenname $gn -surname $sn -samAccountName $gn.split(" ")[0]+$sn -userprincipalname $sn+"#kfriese.com" -path "OUName" -whatif

Answer 2

Here is a more advanced and robust way to do it: a custom function, that makes use of PowerShell integrated functionality.
It uses attributes that make the parameters mandatory, so user input will automatically be inquired when the function is called. Also a validation attribute to make sure the input is not empty and has no invalid characters (you might want to adjust the regex according to your needs).
The arguments for New-ADUser are passed using splatting. The rest is pretty straight-forward...
function makeuser {
param(
[Parameter(Mandatory, Position = 0)]
[ValidatePattern("[a-z]+")]
[string]$GivenName,
[Parameter(Mandatory, Position = 1)]
[ValidatePattern("[a-z]+")]
[string]$Surname
)
$params = #{
GivenName = $GivenName
Surname = $Surname
SamAccountName = $GivenName[0] + $Surname
UserPrincipalName = $Surname + "#kfriese.com"
Path = "OUName"
}
New-AdUser #params
}
To call the function, just type (parameter values will be inquired automatically)
makeuser
Or specify the values explicitly:
makeuser -GivenName Foo -Surname Bar
# or
makeuser foo bar