Adding users to WordPress

From the dashboard of your WordPress website navigate to the "Users" section

Click [Add New] and then fill in your details. The following fields are compulsory.

Username : What you will log in with
Email : Your email address, used for resetting your password

Password : The password you will use to log in.
Role : What level of access you will have to the site.

The click [Add New User]

User Roles Explained

Administrator - Can do everything. 

Editor - Can manage content, but not plugins and themes.

Author - Can create and edit their own content

Contributor - Can add content but needs someone else to publish

Subscriber - No admin access