How can I change the Full Screen background so that it doesn't start automatically with the beach background. I'm not a fan of that background but when I click on the full screen action it always goes there first.

It doesn't do that for me. It has always started a scene selected at random from whatever scenes that I have enabled.

Also, I noticed in settings that the full screen drop down only has "image 1" as a selection.

I am not sure what you mean. Are you refering to the Full Screen/Screen setting dropdown menu which for me currently offers only "Screen 1", but if I plug in an external monitor it has always offered me a choice of "Screen 1" and "Screen 2".