Different type of registrant of your site is an user. An user has many roles in WordPress. As an admin, you can specify the default role of a new registered user or you can later edit and delete an user. All you can do from the admin panel. You need to click on Users menu to delete, change, add an user.
Lets learn how to work with the Users menu of admin panel.
How to add a new user?
To add a new user, navigate to Users > Add New , you will see the following field to fill in the information of a new user. You can specify a role for the user at bottom. Then click on Add New User so that the new user will be created and an email will be sent to notify.
How to delete or edit an existing user?
To delete an existing user, click on Users > All Users , you will get the below screen. Hover over an user, you will get option to delete and edit. Click on Delete to delete the user
How to edit own user profile?
To edit or modify your own role in WordPress, navigate to Users > Your Profile . You will get a lot options to add or change your information.
hope this is clear to you how to edit, add, delete a new user on your WordPress site. Let me know if you face any problem working with users of your site.