I know you’re feeling discouraged, but you must not allow yourself to feel defeated.
Remember the ways in which this event was a success: today you took reached a landmark in your networking efforts. You met with a relative stranger and discussed jobs and careers with him. You tried to understand and be intelligent and ask for advice. Could it have gone better? Of course. But this was the first attempt. To your credit, you knew very very little about his career, background, credentials, etc. before the meeting, so therefore it was hard to come prepared with insightful quesrtions.
You learned that project management is something that deserves further research.
You have established a contact who you can now him and ask additional questions and perhaps get a reference from. You practived conversational skills.
You have started to network. This is a big deal.
What did you expect? A job offer? This is a slow process, but a very powerful one. Don’t stop now. Don’t hit it and quit it.
Remember how many first-time successes you’ve had? Don’t make this another. Take the time to refine your technique and go a little deeper.