It's good to hear that you will start your college life soon. You can start by telling something about yourself. i.e. your name; where are you from? How and why did you choose this school/class? What is your major? What do you expect from this school/class? What is your future goal? What do you want to be?
Then you can talk about your personalities....What kind of person you are? What are you good at? What is your favorite movie, people and color, pet? etc...........
Good luck and best wishes for your new chapter of life!