low storage message constantly popping up

Can someone help me? I am constantly getting low storage warning and I don't have much on phone. Atleast once a week I go through my files and delete items and still not able to update anything or download. Any help or suggestions would be greatly appreciated!!!

popping sound from back leather cover

Hello, just recently picked up a factory refurbished Note pro 12.2 on Amazon and noticed that if I pressed on the top left corner of the backside, it was a bit loose and would create a slight "pop" or click sound. It wasn't too big of a deal but it bothered me and I returned it for another, the new one also has this problem but to a lesser extent. Is this a common issue with the note pro or could it be because mine is refurbished? Is there any way to fix it or should I just try and not worry about it? Thanks for any suggestions!