If you click through to the dialer, then click on "logs" at the top, it should clear the missed call.

If the "i" at the top dosn't disappear, pull down the notifcation centre and press "clear" on the top right - just under the icons.

As for the sound, have you tried a restart? (I know it sounds silly, but sometimes it's all that's needed)

 

Pretty sure your notifications are turned off, that's why theres no sound. I assume you mean for texts/emails etc and not just the whole phone.

If you drag down the drop down notification centre, scroll left/right till you see notifications and you can turn it back on from there.

 

Samsung really should put something like "notifications are turned off, tap here to re enable them" in the notification bar or something.