Young adult [Poland] looking for advice.

I'm an 18-year old starting college (administration major) in a month. I'm looking forward to a career as an EA or a similar profession, although the vision is ridiculously far-fetched as of right now. Getting to the point, what can I do to prepare myself? What skills would be the most beneficial to learn at an age like this, what software should I familiarize myself with and on what certificates should I set my sights on? Currently, all I have is a Cambridge C1 English certificate and REALLY basic MS Office knowledge.