Ok, ok. Since I hate to see threads go unaswered, I'll bite.
What do you have to lose (besides your time if you really don't want to be there)? If you really don't want to attend or think being seen with your friend is not a good idea, decline the invitation. If you do accept, then go with your friend and have fun. It doesn't matter if you aren't sure if you will be attending that school in the future or not. If you are interested, then perhaps the sorority sponsored event(s) you attend will give you more perspective.