If you need detalied information about active directory ldap attributes like size of the field or the data type accepted you can use the msdn documentation:
If you try to change the "name" ldap attribute of an Active Directory object using the Set-ADUser / Set-ADComputer or any other comdlet that can modify object properties you will get an error message like this:
Set-ADUser : The attribute cannot be modified because it is owned by the system
In order to chnage the "name" ldap attribute use the Rename-ADObject cmdlet.
to transform the first letter of a word (or the first letter of every word of a phrase) to title case you can use ToTitleCase method of Get-Culture command: