The simple answer to that will be “don’t waste your initial years”. I did waste it.
As you have posed this question, i hope you won’t be doing so
Most of the times, students waste their first 1 or 2 years, then only they realize that they should have done something.
Also gpa matters so get good marks.
So now actually answering your question. Try to gain expertise in any one programming language (like c,c++,python or java).Take some course other than your college(I would prefer it). Learn some data structures and algorithm(don’t stress on it as it will be part of your syllabus in 2nd year.
Also try to explore some other latest fields in Computer Science to find out what excites you most, read articles, watch youtube videos and so on.