my newborn baby stomach is verry gussy and hard what happened and what I can do

A. is very common under 6 months of age bcz of gas in stomach , burping is solution Burp properly after each and every feed for at least 10 min or till baby take 4 burp.   Give Tummy time 4-5 times in a day time  If still issue persist then   Give colic aid drops 0.5 ml (if needed). Maximum 4times per day.