How to set "Multiple Alerts: in Calendar?

My calendar has recently changed-and much for the worse. The two features I have noticed have gone are both what I used to rely on.

I always used the two alerts for an event: for instance, on a distant event, I would be reminded a week before-then on the day of the event. Now my calendar only has one alert. Why has Apple taken it upon itself to remove this feature?

The second one that I really miss is they have removed the ability to attach a file into the "notes" section. I used this all the time to attach tickets etc to various events. Its loss is a considerable inconvenience.

Is there any I can revert to my previous-much better-calendar?

[Re-Titled by Moderator]