Hi Ghe,
Thank you so much for visiting the Disney Parks Moms Panel with your question! We on the panel love helping guests to plan magical vacations.
You cannot take selfie sticks into the Walt Disney World theme parks. You can; however, bring in your own food. I often bring in my own food. I really like to have snacks in my backpack for when members of my traveling party get hungry and we are not in a situation to head to a dining location immediately. I carry bottled water and soda, as well as an assortment of snacks such as granola bars, pretzels, and fruit. Items that you cannot bring into the Disney theme parks include anything in glass containers, and alcohol.
Take a look at this list of
restricted personal items for a list of items that cannot come into the Disney theme parks. Also be sure that your cooler or bag conforms to the dimensions listed when you are preparing your food for the theme parks.
I hope that this information is helpful for you, Ghe! Have a great time planning your magical vacation, and please do let us know if you have any further questions.