I will be introduced to a VC on monday (by my previous CEO), but I'm in a very early stage (no demo yet) and I don't want any money (well, apart from donations).
How, can I make profit of this kind of meetings ? I understand that networking is important in my position, but I don't know what I can give to this guy nor what he can bring me.
I would definitely not push anything in a first meeting, but I would be prepared to respond to any question. You don't mention whether this introduction is over a meal - all the more reason to relax, take it easy, and enjoy.
I would definitely spend some time up front preparing. Mentally have a list of any possible question and your response. Also, learn something about the VC. You already have a mutual contact (your previous CEO), so you should have something interesting to talk about besides your project. Remember, he is interested in YOU as much as your work. Give him a chance to get to know you.
Most of all, do or say something that will make him remember you, so whenever you follow up, he'll immediately know who you are. A light discussion about the local football team or an activity one of his children is involved in may work. A hand written thank you note is always nice (Why doesn't anyone do this much any more?) But beware: you MUST be sincere in whatever you say or do or you'll look like a jerk and do more harm than good.
Most of all, have a good time! And post back to let us know how it went. I, for one, will be looking for your post.