It's a good rule of thumb that the more education you have, the better. Most entry-level retail sales associate jobs don't require you to have a degree, but most places will require that you have at least a high school diploma. If you're interested in someday becoming a manager, a college degree may be required.
You probably won't get a job selling Porsches right off the bat. Many entry-level sales associates start off selling small-ticket items, such as cosmetics. As they gain experience they move up to bigger items, like electronics and jewelry. After that, it's common to see sales associates move into management positions. A college degree, especially one with a concentration in business, will help you out if you're hoping to be a retail sales manager.