Best practices is you want to be sure you are converting your leads! There is no way to mass convert leads all at once from your leads page. You want to be sure you're working through your leads page efficiently.
If a lead is inquiring and valid, you will then want to convert the lead to a prospect event. Prospect events are the beginning stages of a booking and will allow overlap amongst other prospect events.
If the lead is not justified by you or your team, and does not want to move forward with the booking process, you will then want to convert the event to a Contact/Account. That will preserve their information on your site for future use in case they would like to book again, or you would like to reach out in the future.