Yes your food will be included in the cruise ship fares that you pay.
When you go on a cruise ship there will be a main dining room and buffet and that food in the buffet in the main dining room comes included with your cruise ship fare.
So you can eat your breakfast, lunch and dinner on the cruise ship at no extra charge in the main dining room.
However there can be some other food vendors on the cruise ship that is not included in your fare for the cruise ship and those other food vendors you'll need to pay extra for those foods if you want them.
But you do get your main meals on the cruise ships without needing to pay extra.
When you signup for a cruise ship cruise it should say that the food is included.