Sounds like none of your wishes are possible as of now.
First off, for your time-based alarm, we don’t have time-based triggers inside Glide. You would need to use third-party services like Integromat or Zapier to send an email or a text message to your device.
Second, for your notification thing, iOS does not support native notifications for PWAs, Android supports it only to a certain extent with Glide, so that’s also a no.
Finally, this is also a no. You can’t use custom sounds for now with Glide, even less so for your use case, which is native notification.