The directory folder on the upper left with the arrow heads can be double clicked to go up a directory. Double clicking on it opens that directory. These menu options are all self-explanatory. For the File button there are numerous options, including select all and delete, a combination that would empty a directory. Under Folder are the options make a new directory or go directly to a new directory, so that you don't have to click through the entire directory tree to go from top to bottom, chasing folder icons.
Home is a convenient option as well.
A portion of the directory tree can be shown instead or you may elect to show the hidden files. Or we can drag a directory folder out of the File Manager onto the root window and release. The moving process is simply done by selecting a file with the left mouse button and then dragging the file from one directory window to the other. To copy files, you do the same using the middle mouse button. More about this later.