bbPress.org

Are you using a standalone bbPress installation or the WordPress plugin?

Regarding tags, here’s some answers to be found on this website:

https://bbpress.org/forums/topic/how-do-i-delete-tags

https://bbpress.org/forums/topic/remove-tags

https://bbpress.org/forums/topic/completely-remove-tags

Regarding users:

https://bbpress.org/forums/topic/how-do-you-delete-users

https://bbpress.org/forums/topic/delete-users-with-no-posts

https://bbpress.org/forums/topic/delete-user-and-all-users-posts

https://bbpress.org/plugins/topic/mass-delete-users/

From what I understand, both can done from your admin panel.

If you’re using bbPress as a plugin, you’ll find what you’re looking for here:

Users can be managed from: http://www.yourwebsite.com/wp-admin/users.php

Tags can managed from: http://www.yourwebsite.com/wp-admin/edit-tags.php