Customizing the reminder. Currently, the reminders are carried out by a one-time vibration (which is too easy to miss)

What settings do you go to to make them say, do 5 loud beeps or something?

This is for note 3.
You can add more reminders for one single event.
If you want something more "loud" you should edit the notification sound to something like a longer notifications sound so that it will vibrate for all the sound duration.