It's important to specialize in the type of magic you wish to present. Find an area that you feel comfortable with and that your wallet allows.
Several areas require specialized training and years of study. Other fields require massive amounts of financial investment. Some require little more than several fifty-cent pieces or a deck of cards. Some people have the personality and stage-presence to appear before crowds of 500 people of more. Others can only stand the sustained glares of one or two close friends. You need to decide for yourself.
Please note, that just because you choose to specialize in a field doesn't mean that you shouldn't dabble in any other field.