You will need to start with your own profile, which you can create once you have received this email from us.
Once you have completed your profile, click on 'organisation members'.
Which looks like this, remember, you can only invite as many members as licences purchased. You can always secure more licences by talking with email@example.com.
You can now invite new members, either one by one, or as a bulk invitation (CSV file only).
You can also take this time to create teams, assign a 'Team Leader' (perhaps a Departmental Head or a Manager) and they, in turn, can invite their people onto Ethical Angel.