I've been in college since Fall of '06. During that time, I have made a lot of decisions that have changed my life. I've changed my major about a half a dozen times. I've had many jobs in the past, a girlfriend that I moved in with, friends I've moved in with, and finally moved out on my own. I've even tried being homeless a couple of times: a few once with a job, and several times without one--either couch hopping or living in the campus library. I have done a lot of things to try and make getting through college easier, while at the same time trying to grow up, and what I've come to realize is that sometimes it's easier to take things slowly.
So what I've come to understand is that it can definitely be exciting, fun, challenging and stressful to make major life decisions on a whim. Even when I've given things a lot of thought and planned out exactly how I was going to go about things, it hasn't always been as amazing as I thought it would be. For instance, I hated the idea of working all the time just to pay rent and buy food. So I decided it was better to live in my car. I planned out exactly where I was going to shower (24 hour fitness), where I was going to keep my belongings (in my car), how I was going to make my food (hot plate), and where I was going to sleep (outside of friends' houses or in front of 24-hour establishments). However, despite my planning, things got out of hand. I ended up moving back in with my parents, still with my job, and later ended up quitting all together.
In college, it's important to try new things, and explore new possibilities, but sometimes, it's better to take things slowly. If you want to grow up, get a job, move out, and live your own life, try taking those things one at a time.
First, try helping out around the house. Perhaps volunteer at some place that sounds like you might enjoy it and try to figure out if you could even handle doing that full time or even part time while going to school. If you really want to make your mark on this world or live a comfortable life, school is important, and it should always come first.
Second, try getting a part time job on weekends. Make arrangements with your parents to pay part of the grocery bill, or the electric, or something small. This is great practice for when you really move out. It will give you a sense of how difficult it might be to keep your grades up without any serious repercussions of jeopardizing your how situation.
Then maybe try getting more hours at your job, or get another job that offers more hours. Consider who you would move out with (if anybody) if you did move out. And chances are, if you can't even manage living with your parents, you probably will have a hard time living with friends.
Once you sign that lease, however, you really only have two options: follow through with your obligation to pay rent for the duration of the lease, or mess up your credit for just about the entire time you will be in college. It's really not worth finding out whether you can handle it the hard way (by jumping right into it) because chances are, you will revert to survival mode and pick money over good grades like I have. And even if you manage to somehow pull it off, you might be jeopardizing your happiness instead.
Always remember: no matter how hard life gets, school is important, and no matter what your situation is, your life will always be harder in the future if you don't complete your schooling. Whether you want to help people or just make lots of money, you should always be focused on your long-term goals and realize what is more important, which is learning a lot of good knowledge and using that knowledge to achieve your goals and dreams.
Keep dreaming kids, but always remember what you must do to get there.