I have a couple of suggestions, and look forward to Stephen's feedback.
For children, it's actually much easier than you think. Once children are given permission to try foods, and given the skills to identify the (usually very few!) plants that shouldn't be consumed in your region, they usually flourish with it. I remember how amazed I was when my oldest son, only about 15 months old at the time and barely verbal, looked at
wood sorrel, made eye contact as if to make sure it was okay, then picked it himself and ate it. Of
course, I'd showed it to him many times before, and he'd eaten it and liked it. I suggest starting with interesting or unique flavoured herbs. Anise Hyssop or Sweet Cicely with their sweet anise flavour are favourites of my kids, but they will take something like chives or sorrel and just munch it by the handful too. Even stronger herbal flavours like mint or thyme are sometimes enjoyed raw straight off the plant.
In terms of structures to help expose people in general, I would suggest 'weed eater' walks around a property in a neighbourhood by someone who knows a bit about
local edible plants. You'll end up attracting people you might not expect, who will then be that much closer to understanding where you are coming from. Have lots of 'free samples' during the walk, and a big plate of salad that everyone picked together at the end. I prefer dong a (non-sprayed)
lawn and ornamental bed for something that's really introductory - it might act more as a gateway to wild foraging, and hopefully open some peoples' eyes to the uses of plants they've been pulling as weeds for years. If purslane tastes so good and is super healthy, why are we pulling it out all the time? You can raise some important questions to get people thinking.
Another idea would be to invite people to full perennial meals, though in my mind, this takes more
experience if you are going to put together a full meal that will be palatable to newbies - especially if you restrict yourself to only self-harvested food. It also requires more time to gather
enough food (unless the gathering and processing is a group effort as well), and more consideration of the seasons. While salads can be picked at almost any time of the growing season, other perennials have a limited time when they are at their peak edibility.