Tip:
In the Sounds settings, if you have the Change With Buttons switch on, your alert/alarm/notifications volume will be the same as the iPad's system volume. It goes up and down with the buttons and sliders.
If you turn this option off, then those sounds will always be at the volume set in the Sounds settings (and that volume slider won't change except in settings).
This is the best way to make sure you always get your alarms, even if you turn down the sound and forget.
To stop 'all' sounds when the Change With Buttons option is off, turn your sound down and turn Mute on. Mute only affects the system sounds, not music or other audio apps.