I do not know what a "homeschool ticket" is, but if it is not part of a package, then you have to book a package with a 1 day base ticket to get free dining. You have several options here. You can book the package with the 1 day base ticket and then alter that reservation later to add the free dining discount. If you don't get the discount, you can cancel that reservation and rebook it as a room-only reservation. You can also book a room-only reservation and change it to a package reservation when free dining comes out. This means the room-only will have to be cancelled and rebooked as a package. If you intend to call as soon as free dining is released, this shouldn't be a problem - if you have a Disney Visa card, even better, as Visa cardholders get to call before the general public does.
In both situations, the free dining package has to be available for the dates and resort you want, so I'd call as soon as possible or have a
travel agent poised to make the change for you, if you prefer to use a travel agent.