Thank youu for your help ladies
He should be seen by his Pedi to make sure it's not something. Try using a cool mist humidifier in the room though that helps a lot with coughs. Hope he feels better.
Suction his nose... Its normal for new babies to cough and sneeze due to their systems still adjusting to being outside to uterus. If it continues and becomes regular (as opposed to just intermittent) or becomes bothersome for him to sleep then he should be seen