What order will my stomach digest these food?!
Answers: If I eat an apple first then a fish and then a piece of steak one after another, what order will my stomach digest those food?
I don't think your digestive system plays favorites. The first thing you eat---whatever it is---will be the first thing your stomach begins to work on. If you eat three things, you'll digest three things simultaneously.
However, among those three choices, the apple will be metabolized more quickly than the fish, which in turn will be digested more quickly than the steak. That's just a matter of digestibility, protein content, fiber content, moisture content, and other factors. The order in which you eat the foods really doesn't matter much.