Hello to you both. I'm a second-year terp student at GBC. This post popped up on Google just today; sorry I'm late to the party. Hopefully I can guide you both with some basic info.
Nanelle, the "pre-cursor" program (C114), affectionately known as "ADSP", is very strongly recommended by the department. It's direct instruction in ASL, gestures, Deaf Culture classes, computers, English, and so on. The program is very comprehensive, and is excellent for beginners. Welcome aboard!
Honey.Toronto, you're right - there is a screening to get into the ASL-English Interpreter Program (AEIP, C110). You will receive more information about it as you go through ADSP, but in a nutshell, it's to objectively evaluate your ASL and English skills, as well as get a sense of who you are. Don't stress about it just yet!
Registration takes place roughly in mid-July. ADSP usually accepts about 80 students, and splits them up into smaller groups of 20. Your books will be waiting for you in the bookstore, but if you can buy 'em used... go for it! There are lots of other little things to know too, but these will all be explained to you by your teachers.
Go into it with an open mind and a positive attitude, and you'll be fine.
Good luck!