Congratulations on making the decision to book yet another step in your marriage adventure next week by booking your Honeymoon at the Wilderness lodge.
Just to add the great answer from
@Wood Nymph about your specific Gift Card question.
You also need to keep your new empty Gift card. That way if for any reason Disney needs to refund you, they will put the funds back on the Gift card.
Another handy idea is that you can combine multiple Disney Gift cards to a Max of $1000 on a single card.
https://www.disneygiftcard.com/
A Disney Gift Card can be reloaded for any amount between $5 - $1,000 provided the total gift card balance does not exceed $1,000. A Disney Gift Card can be reloaded at any Disney location that sells Disney Gift Cards
Dave