Newborns sometimes take some time to adjust to breast feeding. I do not know whether the baby is preterm or full term, but you need to start latching as much as possible , before you give top feeds/formula feeds.
After top feeds baby will not take breast milk well till hungry enough for next feed
And while latching, keep stimulating baby if falling asleep
Good burping is the key to this, and after every feeds , 10-15 mins of keeping baby on shoulder needs to be done, regardless of whether baby is giving a burp or not.
Next Steps
Kindly consult for any further queries