Join & Update Notifications
You could use the extension CiviRules to do that.

You need to set up two different Rules, one for each process.

Select a trigger and condition with your requirements (group contact is added, and contact is changed, would be the triggers I think)

Dependent on your preference, you could create one of these actions:


a scheduled activity assigned to a backend staff
a tag (that could be shown in a report on your dashboard)
send you an email (then you need to install the Email API as well, and choose to send email to alternate email adress)
send you an sms (then you need to install the SMS API as well, and choose to send sms to alternate phone number)