Do I have to manually activate every user-account?

Hi. I have created a few user accounts to
different email addresses, so that I can check/test a few things as a regular user and not just as admin.

I receive an e-mail from WiBBLE with my username and password and this link http://wibble.bluebit.co.uk/wp-login.php but when I go here and enter those username and password details (eg Username: testing001 Password: wobble) it says "Sorry, this account is not active."

So then I realised that I could see all the user accounts in the backend in the 'Users' section and they're all listed in the Members section (not as paid members, just regular site users) http://wibble.bluebit.co.uk/wp-admin/admin.php?page=membershipmembers.

And it says 'inactive' underneath them all, so I activated one, and it works. However, my question is:

Do I need to manually activate all user accounts? I want them to instantly be able to use the site and I may not be around to manually activate them? I notice you can 'toggle activation' but you still need to manually select the users to carry out this 'bulk action' with.

Please advise how users can be automatically activated as soon as they sign up?

Thank you.
Kind regards
Cheryl