As a person coming from a computational background, I have been through formal training in computer science branches e.g. software, algorithm, statistics, etc. These skills are very useful in computational biology and put you on a big advantage by giving you a diverse set of tools to approach different biological questions. However, I think it is also a necessity to develop a core knowledge of the underlying biology in order to fully appreciate the science you do; to ask relevant questions and pick the relevant computational technique to solve it.
Here, I gathered a list of topics that I believe are the core of the biology which any biologist, including computational biologists for our matter, could benefit from learning about them. Of course, Learning is a life-long process and no one can imagine mastering all of these topics totally or even near that, but I try to learn about them more whenever I find some times. There are very nice textbooks or online courses that you could take for free, so the limit is your imagination and time 🙂
Biology and Science:
Chemistry (General, Organic Chemistry and Biochemistry)
Physics (General, Biophysics)
Cell and Molecular Biology
Human Genetic
Immunology
Anatomy and Physiology
Microbiology
Pathologic Basis of Disease (Introductory)
Principles of Pharmacology (Introductory)
Histology