An MSN gives you lots
of additional opportunities in nursing -- it is the gateway into the four advanced practice roles (nurse practitioner, clinical nurse specialist, nurse midwife, or nurse anesthetist). It is also often required (depending on the institution) for promotion into higher levels of nursing adminstration, and is the minimum credential (in most schools) for getting a teaching job.
There are lots of programs now that will take you right into a MSN program without any nursing experience, but I (personally) can't imagine how you could make an informed decision about whether you want to pursue a higher degree
in nursing without having any spent time in the field as a generalist nurse and figuring out whether or not you want to make a career in nursing. For one thing, many of us started out in nursing school sure that we knew what we wanted to specialize in for our careers, only to change our minds later on as we gained experience in different clinical rotations. Generalist nurses have much more flexibility to change specialty areas -- once you have an advanced degree and are credentialed in an advanced practice role, you can't just decide that you'd rather do something different (not without going back to school for additional education). It seems to me that it would be an awful shame to go to all the trouble and expense of getting a graduate degree in nursing and then have it turn out after a while that that isn't really what you want to do ...
I was an RN for ten years before returning to grad school to take an MSN, and it was a logical extension of my practice up to that point -- I had gotten as far in my specialty as I could go as a generalist, and I was ready to take the next step.
However, different strokes for different folks ...
I would encourage you to explore and research further, and make sure that you want to make a career in nursing, in general, before taking on the challenge of an advanced degree. Best wishes!