Hi @hbaraka – welcome to the forum.
Lovely to hear you want to get your children into gardening 🙂 You can cut out a small say 4′ by 2′ patch in the turf, resurface it with a couple of bags of compost and then plant some radishes, carrots and lettuce.
Alternatively you can get a veg trug or vegepod which make growing really easy.
Hope this helps
all the best