I trying for first time to set a scene of houses on street and need a "sky" background.  my first try came out too vehemently and I need to delete and try a lighter shade? how delete background?

drawn

How did you originally apply the background scene?  If you imported the background picture, you will need to enter the Material Room and set Background from the pull down menu under Object.  You can delete the image in the BG Picture node.