I'm a very frequent Delta flier so I know this from experience. The layover in CVG is no problem at all. You can easily change planes there in as little as 20 minutes.
Your layover in ATL is pretty tight though. It is a legal connection, but if you can get your flights changed to something longer I'd go ahead and do it especially as you aren't familiar with things there. If you are stuck with this connection do this; try to get a seat as far to the front of the aircraft as possible, travel as light as possible, walk as fast as possible from your arrival gate to the departure gate without stopping for food or restroom along the way. If after all that you still don't make the connection, don't panic. Delta will have recognized you didn't make it and will do its best to reschedule you on the next available flight to your destination that still has room. If this happens, don't stand in a long line waiting for somebody to help you. Instead, call Delta's 800 number and they will re-book you with minimal waiting.
Good luck.