For the most part, you can name a registered dog whatever you desire.
It is not required or necessarily common to name after the dog's parents.
You cannot copy a registered name from another dog, at least, not verbatum.
Usually you need to have permission to use the kennel name from the breeder, especially if their kennel name is registered.
I always recommend something unique.. nothing too common....such as a simple, single name...like *Buddy*, because if you do, it will most likely come back with a roman numeral behind it that the AKC has added. AKC also has rules about not using names like....*Champ*, among a few others....and they also have a limitation on the number of characters in a registered name.
You can check out AKC to see their rules.
Hope this helps.