Ask HN: What advice would you give to a computer science undergraduate?

I am about to enter into the 2nd year of my CS course in university. The second year is when actual CS courses begin. I've had a basic C course. I have good knowledge of basic computer science, some algorithmic knowledge and a good experience with JavaScript and Node.JS. Yet, it would be great if I could get real advice / insights from professional computers scientists on things to explore ( in the CS field ) in college.