Hi Stacey,
Not really a store as such. The local scout troop setup a kitchen/diner for the event, they server breakfast, lunch and dinner for reasonable price. Kandos and Rylstone are about 20-30 mins drive and Mudgee is about 45 mins drive if you want anything more (ice, beer, wine etc).
There is no car movement from Sun down to Sun rise on the site, except for emergency.
Don's roast on the Saturday night is famous
If you can, bring bikes for your kids. The place is reasonably large (100 acres), but quite safe for the kids to roam.