In 18.04 and later launch an application by clicking on its icon in the Dash which is accessed by clicking the 9 dots icon in the lower left corner of the dock. Launch the System Monitor and make a note of the exact spelling of the name of the application that you just opened. Open the terminal and type:
type application-name
It takes only a few seconds to get the path to an application in Ubuntu 14.04 and later. Search for the application in the Dash and then drag the application's icon into the terminal. The application's full path will be shown in the terminal automatically. Dragging the icon into the terminal will also show the path to any file, folder, archive or anything else that has an icon.
In Ubuntu 20.04 and later drag and drop of files or directories doesn't work from the desktop, but does work in other locations including dragging from the desktop in Files file manager.
.desktop
files for each app are located in/usr/share/applications
but not always. Would you consider a shell script that I can write and show how to set up , or you do not want to deal with command-line at all ? The script can determine each file's location and exact location of the executable binary