15 month old baby with cough and green mucus from nose. how should i treat?

Nasal wash out: Nasal mucus will eventually color over time due to the common germs living on the nasal mucus. By itself it doesn't require any effort beyond the everyday need to keep their nose clear. A good nasal washout with nasal saline can help them breathe. Cough/cold meds are not considered helpful in that age group. Attention to comfort/fluids & nutrition are the basics.