There are so many things to learn that you cannot possibly master them all (you probably won't find them all interesting anyway, or maybe you'll see a specialization you'll like!) but learning new skills and keywords to google later makes you really adaptable and feel more comfortable just diving into the unknown. Having a broad knowledge base also makes learning new skills later feel WAY less daunting- approaching a totally foreign concept in something like a MOOC is much less scary when they use words or concepts you've encountered before. (e.g. I didnt do any ML when I was an undergrad, but all the statistics I took helped me through the coursera ML course later).
Do internships- the real world is very different from school and you want to get exposure to it before it comes- it makes you far more attractive as a candidate when looking for work.
And make sure to surround yourself with other curious people, that's a habit that'll help you your whole life.