What Could Be Causing My Newborn Child To Struggle With Breathing, Cough, And Be Lethargic?

Hello, we have 1 month old who has started to struggle breathing since Saturday/Sunday. He has no fever but coughs a bit a green stuff came out of his nose. The main thing is the struggle to breath and he is not totally himself. Kind of lethargic sometimes. We counted his breaths and the average was 32/ minute out of 7 test. No fever what so ever.