Most often colleges do not require that you have computer experience before starting the program but this may change as more and more students come into the major with computer skills. Since most highschools do not teach computer art in the curriculum, it is rare that a college would require computer art skills prior to entering. It is easier to learn computer skills than learn how to create art if you have never drawn or worked with art before. All areas within computer art require that you be able to work with color and composition and artistic idea development. Some areas require good drawing skills while others depend on your ability to work with 3D sculptural forms.
Many schools require an art portfolio before entering into a computer art major.
It is important to be a hardworking person. This is not a major for any one who is interested in the easy way out. Computer Art is changing faster than most other areas and you have to be a lifelong learner to keep up with it. The computer does not make the creation of the art faster or easier. It allows the artist to create art that is different than that which is created using other means.