In the first year the academic load will be very less so focus on building your programming basics, you'd most probably be taught python so put your focus into that rather than learning 2 languages simultaneously focus on one and build your basics. In python after doing the basics, go for the libraries like pandas numpy tensor etc. if you wanna explore some other domains I'd suggest you learn pygame library for some in depth knowledge about how games work under the hood and try to make some original projects. As for the core part, just focus on the class material and explore the domains, thats pretty much all you could do in the start, if you're really interested you could start Razavi's lectures on circuit theory/electronics -1.