I have no idea how to make this shortcut or if it’s even possible. I would like to like to get a notification to remind me of calendar events and also anytime I add or change a calendar event in a certain calendar Is this even possible?
That is a standard feature of calendar events to have. Look for the “alert” setting on an IOS Calendar event for example.
There is no trigger there, so you would have to keep a copy and periodically scan for differences. When a difference is found, add/ modify the event and trigger a notification. Certainly a non-trivial execution in Shortcuts.
However, I am not sure what the purpose of this would be. You say that you are making those changes or additions, so why would you need to be notified of them? Even if you assume they were automations that you were not applying what purpose would it serve? Is it some sort of forecasting calendar? Knowing the context might (?) yield an alternative way of approaching things - e.g. a daily or weekly check.
It’s a shared calendar, and the other person doesn’t pay attention to the alerts. So I was thinking maybe something could be sent as a text or notification.
Have you considered asking them to change their calendar alert sound to something more annoying than the default so it isn’t as easy for them to overlook?
They are already being alerted in one way so it might be better to try and make that alert work better for them rather than adding others with a strong risk of them similarly overlooked.
If lack of awareness of the alert isn’t the root cause, and they choose to ignore it, then it may be time for a carrot/stick approach with the individual. 