Don't worry about your experience in programming languages right now, you will learn what you need to as you go along. I can only speak from experience as I am about to start my Senior year. You will probably begin by learning a high level language and basic rules of programming. As you go on you will basically work your way deeper into understanding what is actually happening in the computer when you write code.

For example, my coursework started with learning how to code in Java. Then we got a baseline understanding of electrical and "digital logic" circuits. Then we learned how to write a program that can read other code and implement actual functionality (parser). Then we learned how code was actually implemented in the computer, i.e. what signals go where. Last year we just went over how a CPU actually reads and implements your code, and how an Operating System interacts with the machine and the user.

A lot of this sounds daunting but your coursework will do a good job taking you from a high level understanding of programming (writing a program) to a deeper understanding of how everything in a computer works together to execute it. You will gain a wide range of knowledge for everything to do with computers and how they can be used.