Qualifications
While it's a pretty good idea to have a high school diploma, you really won't need a secondary degree to become a professional driver of VIPs and prom kids. Big surprise—colleges and universities don't offer majors in chauffeuring (although you might want to consider taking business courses if you plan on opening your own company).
That doesn't mean there isn't anywhere you can go to get the kind of hands-on training livery services will expect you to have. Most major cities will have a limo driving school with flexible classes. Courses include defensive driving, safety, driver etiquette, and even bodyguard courses. Even without this training, your can-do attitude and ability to be a people-pleaser might win you a position in a company―after which you can probably expect they'll send you to driving school.
Speaking of people pleasing, being personable is a huge part of working as a successful chauffeur. If you work for a company, every client will be different and it will be your job to bend to their will. If you work for one individual, it'll be even more important. It's this personality distinction that will determine whether you're going to spend your life driving taxis or limousines.