When to cut baby hair? Usually people do it on first month? 4th month or 1 year old? Or do we have to cut on 1 month, 4th month and 1 year? Heard it's good to shave it all and baby hair will be fuller when they grow up? Pardon my ignorant ... :)

It all depends on how much hair your baby has but, generally speaking, do not cut your baby's hair before its first birthday. Up until the age of six months, the "first hairs" grow and then fall out, following a drop in hormones that's completely normal after birth.