If I were you, I would learn something practical, fun to do, and have visible accomplishment. One such example is mobile device (android/iOS) programming. It will not only give you an edge over your classmates, but also you may earn extra bucks as well. If you own macbook+iphone/ipad, swift [https://developer.apple.com/swift/] is a fun language to learn. And Professor Paul Hegarty has made iOS programming much more fun to learn over the years [https://itunes.apple.com/us/course/developing-ios-8-apps-swi...] [http://cs193p.stanford.edu/]. For android programming, you can start from learning java and then jump in to Google's android course [https://www.udacity.com/course/developing-android-apps--ud85...].
You may experiment with arduino or any other embedded systems. You will learn a lot about electronics, and basic computer structure. Embedded systems are integral parts of IoT.