You start with a base image or color, then you do various effects and actions to it to make an amazing end product. Graphic design is way too complex to explain more than that.
its the history of graphic design! from way back to ww1 posters, bauhaus, great typographers, the design of the grid, the golden section, design pioneers!
i would look up Bauhaus,...
Contact the college. They will have a specific type and or model that may be required. They usually have some good prices for the machine and software as well.
If you're going to study graphic...