After clipping or copying a video, audio, image file, you may need to remove the unneeded clip. Here is how to delete a file in the timeline in 3 ways.
Select a file on a track. Click the trash icon to delete the file from the track.
Select a file in a track, right click it and select "Delete Edit". This will only delete the selected file and make no change to other files in the track.
Delete and Indent
Select a file in a track, right click it and select "Delete and indent". This will not only delete the selected file, but move the files that come after forward to cover the empty space created by the deleted file.