Everyone: A camp chair, clothing appropriate for the weather and shoes appropriate for hiking, sunscreen, insect repellent, a flashlight, bottled water or other drinks, plates, cups, and eating utensils.
Campers: A tent, sleeping bag / bedding, personal hygiene products, towel, washcloth, shampoo, soap or body wash, changes of clothes, etc. Drinks and snacks.
Tent decorations: You might consider decorating your tent space. This can include banners, flags, solar lights, or other items of personal interest or that relate to groups / communities that you belong to.
Optional: Glow sticks, extra snacks, car chargers and backup battery packs for your phones and electronic devices, notebook and pen to take notes, and a drum or other percussion instrument for the drum circle.
Items for the Community Altar: Items of personal significance to go on the community altar.
Other: Ritual garb, if you like. Consider a costume / mask to wear to the Samhain Party. Think nature deities and nature spirits - Faeries, Nymphs, Satyrs, Green Man, and so on.