If you have cows though....well, there's your compost.
me and my family would live most property down here that im looking at has either a creek or a pond on it already i would need enough for roughly 10 people and sum animals and a gardened im looking at between 5 to 10 acres do you think i need more
My family and I (and our ranch gal) are 5 people, currently on 5 1/2 acres (in FL). I'd think 10 acres should be fine for what you're describing (of usable area, so not including the creek or pond). Of course, you don't have to go deep for a well here either. You can probably even find some old farmland that already has a well or two. If so, this is good, as these can be very expensive. Also, are you trying to build a house, or looking for an existing? All things to consider.
For me, there's some empty land right behind us, so if a SHTF event happens, and nothing's done with that...well....
Later on, we might look into purchasing it.
Just another thing to consider though....if there is room to grow, for example.