Stinging nettles, chickweed and many other spring greens are available in some temperate climates at this time of year.
It's best to get a local guide book to identify greens safely but what a fun, nutritious activity this is- to wild harvest your greens and then look up delicious ways to prepare the foods, like garlic sautéed nettles or fresh balsamic and olive oil salad with chickweed and other greens! So fun and so yummy!
There are many online guides too! Here is a link to a Pacific Northwest guide. Below find images from their site: nettle leaves, young nettle plants (they must be harvested young) and chickweed!
You might find foraging teachers in your area too to help you learn about the edible plants around you!