When I i open a picture from my Documents it automatically opens in Photoshop. I want it to open in Lightroom. How do I change this preference?
You cannot open an image with LR as you would with Photoshop , or Elements. (or a word document, etc)
The Lightroom program can only open "Catalog" files (*.LRCAT) Opening a .LRCAT file will automatically open Lightroom.
To edit images in LR you must first open the program, then IMPORT the image into the Catalog database (only ever once), then you select the preview thumbnail and go to the Develop module ( press "D")
Your edits in the Develop module will show on the preview in the library grid.
Your original image file is not altered, so will not look any different in File Explorer or Finder.
To get an image file with your Develop edits applied, you must "Export" a derivative file in JPG or TIFF format.