A question reguarding starting my own casual restaurant business.?

I want to start my own restaurant business. I wnat it to be like coffee, pizza, and gelato, and maybe a (bakery). I want it to be like a panera bread and starbucks, along with the pizza and gelato. Do businesses like these get their food from special food distribution companys, if so where can I find out more about them. Is there any food companys that give their food to restaurarnts to sell? Also maybe mexican food too. But remember this is going to be a casual restaurant, like a sit down like a panera bread or cafe. I Would like to have subs and sandwiches also. If possible, I'd like to have natural and organic foodds also. Thanks to any answers that come my way.