You can create a new user either from Active Directory Users or use the Computer snap-in or from PowerShell. I have listed the following steps which can be used to create a user from Active Directory Users and Computer snap-in.
Add New User in Active Directory Domain
1. Go to the Server Manager.
2. Click Tools -> Active Directory Users and Computers.
3. In Active Directory Users and Computers window, expand the domain (click on domain name suppose yourdomain.com).
4. Locate Users container. Right-click on Users -> New -> User.
5. Type first name, last name, and user logon name (suppose firstname.lastname@example.org).
6. Click Next when you are done.
7. Type password and confirm password. Uncheck all boxes.
8. Click Next and then Finish.