Thanks for the question, Danielle!
I'm really lucky to have student employees who are interested in librarianship as a profession - this past spring, I wrote reference letters for four students who applied to library school - so I get a lot of opportunities to wax poetic about my job. However, I try to make it really clear, every time I talk to them, that librarians aren't just book pushers. The job market being what it is, it's smart to hedge your bets and think about which skills are transferable - like database/data management, project management, and records management (all the managements, really).
For me, in terms of tech skills, I think the most important thing was getting used to the command line. Learning a bit of unix, some bash, and how to use git were really formative in making me comfortable with tech. Also important was learning a bit of coding/programming - I started with HTML and CSS, then worked my way up to Javascript, jQuery, and a smidgen of Ruby and Python over the course of about a year. I'm not a programmer, but understanding the possibilities that these languages present - and what makes them different from each other - are good things to know if you think you'll have to talk to programmers on a regular basis.
There are probably a ton of other things, but to sum up in three points:
1. Take the classes that teach you to manage stuff. Those will be important.
2. Get comfortable with your computer. Try creating a git repository from the command line! It's daunting but it will teach you a ton. Git in 15 minutes:
https://try.github.io3. Take some coding classes, either in a collaborative low-risk situation like Software Carpentry or Ladies Learning Code or online somewhere like Codecademy.
I hope this is helpful!
Sara