As a college student you will experience a new level of freedom. You are no longer in your parents' house and living with their rules. No one is going to monitor your comings and goings, know whom you associate with, or see whether or not you are attending classes. While your college will provide you a set of rights that you will enjoy (freedom of speech, access to events, etc.), these will be balanced with a set of responsibilities that you will be asked to adhere to. For example, you will be responsible for exhibiting civil behavior and academic honesty, to name a few. In order to live on campus, you will need to attend classes regularly and respect the policies of the college.
If you violate the policies of the college you could be subject to a conduct hearing. At most colleges this involves a meeting with a conduct officer or a meeting with a committee consisting of some combination of other students, faculty, and staff members. If you are found responsible for a violation of college policies, you will usually be given educational sanctions that (based on severity of the violation) can range from probation to community service, and may go all the way to suspension or dismissal from the college.
When you lived at home and got in trouble at school or somewhere else, your parents might have stepped in to assist you, but now, with the freedom of living on your own comes the necessity to take responsibility for your own actions and behavior. You, like everyone else, are going to make mistakes. This doesn't make you a bad person; in fact, it makes you a human being. What is important is that you own your mistakes and that you learn from them. Don't try to blame others for your actions and don't assume that you are allowed to violate policies and not pay the consequences. A college campus is a community, and the expectation is that you will live up to the standards of that community. Do your best, always tell the truth, and all will work out in the end.