I mean " LPN"

First of all, you should know the differences of each, so you won't get confused and as long as your brain still wants to and does work. If you are ever in a mood for an up and coming area of nursing, try case management.

I want to help people with diets.. Is that what nursing do?

Well case management is a good field, i also suggest you to search about all these when you are satisfied with what you actually wants to do then go for it