There are a number of different career trajectories in CG that link back to your studies in high school. Many roles in the industry that are heavily artistic, so visual art courses, both theoretical and practical are important if you wish to be an animator, designer, modeler, texture artist, matte painter, compositor or lighter.
Animators are performers, so performance studies are also very useful for them.
As computers are one of our most important tools of trade, computer studies are very helpful. These will give you good general understanding and skills relating to using digital technology as well as potentially more skills with specific software used in the industry. With such a heavy reliance on digital technology we have a great crew of IT experts, so studying IT and maths are a solid base for that area.
Managing the workflow is a crucial part of the business of digital production, so if you think you'd like to be in production management and be a coordinator or producer, learning business principles and people management skills could be very helpful.