First of all, start here:
Read every word.
Consider the wisdom of those "in the trenches" lest you repeat their mistakes.
If you are still interested:
Volunteer as an aide. Get a job as an aide.
Follow a nurse on a 12 hour shift for 3 days in a row.
That your income will max out and not progress beyond middle class levels and be happy with this.
That on certain days, you will make an enourmous difference in someones life.
You will never receive adequate compensation or credit for it. You may even be harrassed by family members who hate you for trying. Not to mention your employer with an entirely different "agenda."
Then, after you have become a nurse:
Reflect upon your decision. You'll do it often, for hours on end while trying to sleep.