Can I leave as Co-signer?

OK so i live with my mom. I'm 21 years old and I really didn't know until what 5 minutes ago the responsibilities of the co signer. I DID NOT KNOW AT ALL that I had the responsibility of paying rent when my mom could not. I didn't even have a job when she put me on the co signer. She told me that I couldn't live with her unless I signed it. Once again I did not know that I didn't have to sign it. (Unless someone again knows a little more than me) But my problem now is that I JUST got a job and I want to move out of her house. I don't know when the lease is up and I have no idea how or what I can do to still move out without breaking the law. So my question is simply what the hell can I do at all to move out at the time I want to in order to not break the law and leave to live somewhere else. Also, apparently we (me and my mother are getting sued because she hadn't paid rent in three months) are getting sued. Do I have to appear at court with her, does she have to go, and if we go do you think that this story is a legitimate enough reason to not be part of the suing in the first place. So to put it all in, One what can I do to move out and Two is it a legitimate excuse to tell the judge that I simply did not know. Please this is very important and can effect my entire future and livelihood. Answer as descriptively as possible.