As others have posted, more information would be helpful.
Here are some things that might help:
1. Room Only Reservation: If you book only a room at one of the WD owned hotels, then you do not lose your deposit as long as you cancel at least 5 days prior to your arrive. In this case your deposit is all that you have to pay before arriving at your resort.
2. Package Reservation: A package is when you book your room along with tickets and/or dining plan. In this case you have until 45 days prior to arrival to cancel without losing your deposit. You also have to pay the entire package off at the 45 day mark.