Nose block in newborns is quite common. It bothers most during late night and early morning hours. Most useful treatment is to instill saline drops as often as required. If you find any secretions in the nose don't use a cotton bud to clean the nose from within as this may cause more trauma. After putting saline you may use a mucus aspirator after consulting your pediatrician who shall be able to teach you the technique without causing trauma. This problem should gradually resolve as the baby grows.