What happens if you signed the MPN for the stafford loan , but end up not attending the school .?

I was approved for the subsidized and unsubsidized signed the MPN although my mom was denied the parent plus loan . Now i am not going to be able to attend the school .? What happenssince im going to have to dis enroll will i still owe the loan .?! so confused i will call the school tomorrow and everything but im anixous to have any idea of what's going to happen now HELP :/