2D game-Best way of creating the world.

Hey, i am creating a 2D RPG/Side scroller and i want to create a world that could evolve on its own. AS an example : If you help with the side mission the baker, when you pass another time through the city, the bakery is blossoming ; while if you don't, when you pass through the bakery is closed as they are broke and so long. . .

What would be the best way to do it? =/

BTW this is the first time i am posting on the forum, so if i did, said, wrote, asked something wrong, tell me.

P.S.: I am still a beginner so please keep it simple and clear and if you could include a tutorial, it would be much appreciated