We still have this notion that bringing up children comes instinctively but we humans are not generally ruled by instinct! We have flexible, adaptable minds and our environment is crucial to the way we develop. So looking after a baby, loving a baby is not an “instinct” but partly the product of our own experiences as babies, the way we were loved and looked after.
For the majority of people, that will be totally fine and they will go on to be with their baby the way their parents were with them, that will feel totally natural or “instinctive” to them.
For some, though, their own experiences were not positive and they might find themselves struggling, not wanting to repeat what has happened to them but not knowing what to do instead. So of course, it is a lot more difficult to have to think through what to do, how to react, for example if you have never been praised as a child and you want to praise your own child, it may feel really artificial and strange to say “that is well done!” or express your feelings “I am proud of you!” if that was not modeled for you, so in order to do it, you have to practice over and over again until you get over the artificial sense, the embarrassment, whatever feelings get in the way and know that there is nothing instinctual about it, it comes from your own experience.