Disc Jockey: noun: an individual who plays recorded music at social events or on the radio. Also called DJ.
If you desire to become a mobile DJ, my advice would be to find a mobile disc jockey in your area, one who entertains at weddings, parties and other musical events. Find a professional DJ who would be willing to help and train you. You would have to help him by carrying, setting up and tearing down the equipment. A few months or longer would have to be spent learning the ropes during his performance.
You do need to be outgoing and feel comfortable speaking into a microphone. Look your audience in the eyes and smile. If you have taken acting or speech courses in school you will have an advantage in the mobile DJ industry. Your understanding and knowledge of many genres of music is a must. You will have to take music requests from you audience. You will need a large collection of music, either on compact discs (CDs), or digital MP3 music files played from your computer's hard drive.