Sports, flying, and over 400 student clubs and organizations are available for you to participate in. Watch the Purdue Exponent and bulletin boards during the first month of class for call-outs by these groups. Depending what the problem is, usually you should see your instructor first. Discuss the problem in a professional manner. Suggest some solutions.
Faculty are usually very willing to try and work out problems.
If you are uncomfortable doing that, or don't feel you are receiving any help, contact your adviser or curriculum chair. You can also schedule an appointment with the department head. The important thing to remember is not to ignore your problem. There are ways to solve most issues. First, check with your adviser to determine what is an appropriate change.