Hello!
Every creature needs food to finance it's energy usages. We humans have all the "keys" to open up all the different foods we eat and get the calories out. Thats how it works, on a lock/key kind of mechanism because burning the food won't get the calories out. how did all this food suddenly grow?
The answer lies in the food chain. In order to live, an organism needs energy. The primary ways of getting energy are from heat or light rather than 'food'. Living organisms had to be able to convert some source of energy into chemical energy which is used to 'live'. Such raw energy supplies include sunlight and the earth's warm core.
Once a population of organisms exists that exploits direct energy, a new niche becomes available: instead of taking the light/heat energy and converting it into chemical energy - the existing chemical energy stored in the cells of other organisms can be tapped into. When an organism dies, its chemical energy is just lying there waiting to be tapped.
So the first kind of food was simply other organisms that have either died (scavenger), or (alternatively) were killed by 'predators'.
Food is just other organisms. The food we eat are mostly animals and plants that have been killed by us. So whenever there has been life - there has been food. It didn't suddenly 'grow'.
Isn't it also funny how alot of people enjoy eating food as God made a potentially annoying task of supplying ourselves energy and made it enjoyable?
It seems logical that natural selection would favour organisms that 'enjoyed' eating over those that didn't. Likewise it would favour those that enjoyed eating high energy foods and disliked poisonous foods. There are parts of the brain that release 'feel good' hormones when eating. It is also one of the reasons we enjoy sex.