When I was a teenager I fed 2 adults, 2 teenagers, and a child on a 1/2-acre. There was plenty for all of us to eat and can, and more than enough to share with the neighbors. My best friend and his wife plant a plot aprrox. 50’X30’ and it feeds his whole family for about ½ the year, they do it more to have fresh vegetables than necessity like when I was a kid. Depending on the soil and location an acre would be more than enough for you and a fairly large family leaving some for seed and to trade and barter with.