I am wondering on the process of transferring. I have already decided and was accepted in majoring in history, but I would like to broaden my education depending on what I want to study in grad school. For example, could I take classes generally required for medical school like biology, chemistry etc
yes, you can sign up for any class that isn’t listed as restricted to majors only.
That said, there is a unit cap on how many units you are allowed to take as a student. So plan out a schedule that gets you a degree (they will explain how to do it at orientation, but its not hard, just look up the requirements for a History degree). Then you’ll know how many free units you have to take as you wish.