This is a great question. For long term advice, I would say make sure to learn as much as you can in case you have to move from one area to another. For example, if you start with pediatrics and have to move to ER, there would be different things you would need to know as the environments can be quite different so make sure to learn as much as you can.
Short term advice, I would say would be to attempt to shadow in the field that you are looking at before you actually decide. Some people definitely think they want to go to nursing field and then get in there and find they either do not have the heart or the stomach for it. I would say definitely make sure that you know for sure that this is what you want to do before you actually put in the work and time to get there.
Good luck on your journey