>>33367541
I think the idea is mostly that you bring foods that don't make a messy, don't take further preparation and all around aren't a hassle to eat. So (fruit) salads you prepared in advance or bought premade, for example. Fruits in general. Cheese and a baguette or something, bread you can tear that is sturdy. I would just bring a mix of things, some sweet some savory. If it's hot definitely bring cold (soft) drinks. Alcohol depends on the time and whether the person you're going with usually enjoys that - a lot of people easily get sleepy drinking out in the sun, even if it's just a bit.

Bring oats or sweetcorn for the ducks if you can, bread really messes them up inside.