As the bride and groom you are the hosts of the event - if you're parents are paying they are considered hosts too. So when it comes to getting the party started it's up to the two of you to get things going.
Your guests will follow your lead. If you're on the dance floor they'll want to be on it with you. If you're visiting with each table, many people will remain in their seats because they are waiting to speak with you.
Basically, the more the bride and groom avoid the dance floor the more your guests will.
So if you're hoping that everyone has an amazing time at your wedding and hired a great band or DJ it's important that the two of you enjoy time on the dance floor with your guests. If you guys aren't big dancers there's nothing wrong with planning a formal dinner and hiring musicians specifically to play background music during the meal.
