When I was going back to school for my second career, I knew what I wanted to do but I made a long list of other options. I spent a good bit of time investigating them.
Nursing was on my list, because it was similar to what I wanted and the pay was good... darn good. I have a lot of friends who are nurses who jumped all over me saying "NO! Don't do it! You're the wrong personality! It would kill you!"
They were right, which is fine, cuz I didn't really want to do nursing anyway. But I still looked into it.
If you are serious about nursing, I'd look first into getting a job as a CENA (nurse's assistant) in the kind of facility you'd like to work in. It's a very short training period, gets you right into the field, and often hospitals/clinics/nursing homes will pay part or all of the tuition for their CENAs to go to nursing school.
And you will find out very quickly if this is the kind of work you want.
"If Americans want to live the American Dream, they should go to Denmark." - Richard Wilkinson