My event isn't until later but I would like to allow customers to book reservations for it now. How can I handle this?

You will need to create your Reservation Type with the Start Date as today's date and End Date as the last date of the event. You will then need to add Blackout Dates between now and when the reservation will be available. You will need to add a blackout date for each date. Unfortunately, there is no way to blackout a date range.