If not much direct sunlight, then you are looking at plants that will tolerate shade. That includes some lovely groundcovers (vinca, baby tears, pachysandra, sweet woodruff) but also includes things like ferns and various flowering perennials (dicentra, hellebores, astilbe) and a number of small shrubs. You may want to check at any garden center or retail plant nursery in your area for suggestions and availability.

Most herbs want a good amount of sun......like a LOT......to be happy and grow well. Mint (also parsley) can tolerate the least amount of sunlight.

"small patches of moss." This indicates pretty deep shade that is consistently moist.

Generally, variegated and chartreuse foliage and white/very light colored flowers show up well in shade, and even in the dark. There are a ton of plants for shady gardens, shouldn't be hard to find many 'out there.' I don't know how things are done in France, but it's kind of dull, gardening-wise around here for the next couple months. You might be able to grow some lettuce? I'm not that good at veggies.

In the spring though, you should be able to find tons of cool things like Begonias, Coleus, cool elephant ears, Caladiums, Tradescantias, Plectranthus, Impatiens, sweet potato vines of various colors, Persian Shield, Alternantheras, Perilla, and so many decorative foliage and flowering plants for shade.