It sounds like you have diverse interests, which is great. That will serve you well in your career, and enable you to pursue vastly different positions.
If you have an interest in med-surg, it is a great specialty to start out in. But if you are considering a med-surg position because an instructor has insisted that all new grads should start out there, then don't bother. As BBG has stated, nothing you learn in med-surg will apply to neonates. Most large NICUs in teaching hospitals prefer new grads, since they have nothing to un-learn. Med-surg and adult ICU nurses can transition to the NICU, but it is typically more difficult for them to do so than a new grad with a "clean slate".
As for going the other way, (NICU to med-surg), I really don't know. I've never known anyone who has had a desire to do so. I've known NICU nurses who have left to work in OB, peds, OR, school and clinic nursing, but never adult med-surg.
As you consider your first RN position, it is vitally important to find a unit where you will receive a thorough orientation 1:1 with a consistent preceptor, and that includes both classroom and clinical instruction. I would recommend choosing a unit that has at least 50% experienced staff (meaning at least 2 years of experience on that unit) on all shifts.
While the money may be tempting, be wary of hospitals offering large sign-on bonuses, as that is often a sign of poor staffing. Hospitals with good reputations and good staffing rarely need to offer such bonuses to recruit and retain staff.
Good luck and happy hunting!