Scaling my game for different resolutions?

Basically, I am running my game at a set resolution currently. When I make a stand alone build, I force it to reset the resolution when the main menu loads. I would like to have the game basically scale up for the different resolutions so that regardless of the resolution. I am an amateur coder, and am looking for a pretty simple way to do it.

you can adjust camera’s size on the factor given by the resolution