Rendering/Lighting/Grahpics Issues - Grainy image

I have been working on this project for a little while and am still quite new to UE4 but I have notice that everything looks grainy or blurry. Even when I launch the game it looks bad. Basically could anyone tell me how I make my game look like this ( All I really need is like a tutorial video on how to make my game look halfway decent because in the pictures I have provided everything looks grainy and ****** idk why. Please someone helpUntitled.jpg