Really, this is a question of budgeting, not your career! Take out a piece of paper and at the top, calculate what your monthly take home income is going to be as a CNA. Then list all the various bills and other expenses you will be once you move out. This needs to be as exact as possible because you don't want to find out a few months after moving out that you are not making enough to stay a float. Some things to consider are:
Utilities - call up the apt and ask for an avg so you can have an idea
Food - do not skimp or lie to yourself here! If you currently spend $200 on food now, most likely you are not going to cut this expense down by half or more unless you are really comitited to being a frugal cook and shopper.
Gas - if you have a car, or this could be bus pass,
Car payment - if you have one
Car insurance - if you own a car
Credit cards - not just the minimum balances either or you'll forever being making payments
School expenses - tuition, books, supplies, anything that won't be covered by a student loan or grant
Health & beauty products
Clothes - this doesnt need to be extravagent, but you'll need new scrubs
, socks, underwear, shoes, ect. every now and again. Might as well set money aside each month to do so!
health insurance - if you don't get it through work and have it taken out of your check already.
This are just some basic things to think about expense wise, each person has their own needs, like pet food, day care, personal loan payments, SAVINGS (emergency fund is so important to have!)
If at the end of this, your income is greater than your expenses, then you should be fine. If not, either consider ways to realistically cut down your expenses, or maybe hold off on moving out and going to school until you can increase your income or pay off debt. Hope this helps!