It is important to listen to that person, you never know where it may lead in the future, could be a new co-writer or a good contact for the both of you.
Attitude is altitude. Be a positive person with conversation. Do not complain about the music industry and how you do not like the changes. Be positive and someone that people will want to talk with during the event. No one wants your whining, complaining, disappointments on your journey. Share some kind of excitement and ask about that other person. It is very valuable for the conversation. We have two ears and one mouth for a reason.
When you have talked for a couple minutes, trade business cards. ALWAYS have your business cards with you.
Turn your cell phone off or at least the ringer to vibrate. We all use our phones to take notes. Do NOT sit and text everyone during the events and use your phone to take photos, perhaps FB and Twitter as you arrive at the event, with the news you are excited to attend the event. Do not answer your phone if it rings and you are in your seat during the event. These are basics; however, you would be surprised how often these mistakes happen at events.
As you meet the pros, a couple things NOT to do:
Do not keep them talking longer than a minute or two as there are other people waiting to talk with the pros and panelist. If it is a hit songwriter, do not ask them to write a song with you. This is not the time and they probably do not know you or if they know you, this is not the time to ask them to write a song with you. Do not hand the pros your business card, unless for some reason they would ask for the business card.
Many events do not allow you to record the panel discussion on your phone. Ask before the event starts if recording the panel discussions or workshops is allowed at the event.
During breaks, network with those around you, ask what they thought of the panel discussions or workshop speakers, again what they do, where they are from, or any other positive topics. Refer to above for business card tips.
Learn all you can. Sometimes you may know the topics, yet if even just ONE thing you learned is helpful it is worth attending the event. Stay in touch with the people you met and exchanged your business card and on some of them, set up a time to reconnect with them.
Most of all - Be Positive, Learn and start relationships with some of your peers at the music business events.