If you don't have any money to buy food you can grow a garden to have vegetables to eat. Growing a garden of food takes time though. But you will have some food without money.
Food banks can also provide you with food. Although you might have to prove you have no income somehow.
And believe it or not check in grocery stores dumpsters. Most Grocery stores throw out good food that never really touches the trash and is good enough to eat.
A lot of people find good food in dumpsters. A lot of grocery stores waste a lot of food and it's sad when people are going hungry.