Great GPA and DAT will be highly look upon, but without any extracurricular activities, it may indicate that you are more of a book worm rather than well-rounded person. With that being said, you should try to look at extracurricular activities that you like to do and something that will help your applications in the future. I suggest you joining in organization that will make you unique as a person, and not a cookie-cutting applicant. For example, maybe volunteer at a mentally disabled hospital.