Go on a missions trip if it is feasible. This might be a team trip with your youth group to Mexico. It might be a trip with Teen Missions (http://www.teenmissions.goshen.net/) practically anywhere in the world. Or you could hook up with an inner city (i.e. Cityteam - http://www.cityteam.org) or appalachian ministry here in the US and work with them on a short term basis. Some missions organizations will let you go overseas on a short-term basis to help out a missionary and learn what they do. That might be another option to explore.