A greeting or a short comment about the event can open a conversation. Notice whether the other person responds and stays engaged. They may be spending time with friends, working or enjoying the room alone. Keep your opening brief so they can answer or return to what they were doing.
If you want to dance, exchange contact details or keep talking, say so plainly. Let the person answer that request before proposing another. A previous yes applies to the interaction they accepted. Check again when the plan changes or when they seem hesitant.
Acknowledge a decline and move on. Give the person space and let the conversation end. If they later approach you, consider what they are proposing then. Both people should be able to start and end the interaction comfortably.
