You're going to need a way to get the food from your house to the location of the picnic.
If, rather than eating at a picnic table, you intend to eat on the ground, you should seek for a picnic blanket that is not only foldable, but also water resistant and simple to clean.
A picnic blanket
You are going to require some utensils unless you just plan on providing dishes that can be eaten with your fingers.
Cutlery & napkins
Even if you are not drinking alcohol that is sealed with a cap or a cork, you are still required to do this. It is pretty much a must.
Raw meat for a barbeque requires multiple cutting surfaces. Raw meat is prone to bacterial contamination (and more than one knife).
Cutting board & knives
Maintain a basic first aid kit at all times and carry it with you.
Bring foods that carry well, are mess-free, and are easy to hold. Bring pretzels, popcorn, or chips. These don't deteriorate and are picnic staples.
Food, snacks, and treats
Always carry some type of entertainment, such as a multi-player card game, portable corn-hole, or a guitar.
Games & entertainment
Cleaning is the last thing you want to do on a good day, but it's necessary.