There are likely to be prerequisites for studying graphic design. At the college level, youll need a high school diploma or the equivalent as well as some foundational math courses. You can find out what you need to complete the class by looking at the course guide books provided.
Before enrolling into a graphic design program, find out what current skills and equipment you may need. For example, you may need a laptop with specific software to do the coursework. Is this provided or will you need to purchase it? Define this before getting started.