Well really you need to be very comfortable working on your own stuff to be able to start the path towards being a mechanic, but id imagine depending on your age, if your still in school, start taking shop classes, if your out find a good technical school. Learn on your own time by observing a friend or someone who knows there way around cars, then start taking on little things your self, try tougher jobs with the use of a shop manual. Best way to become a mechanic is to show proficiency in all things automotive.