The easiest way to move files in File Manager is to open two copies of File Manager and drag and drop files between the two.

To start another copy of File Manager you can just select it from the Main Menu Button. Once the second copy of File Manager is open you can simply click and hold the right mouse button on the file you want to move and, while still holding the mouse button, drag the file to the second copy of File Manager. Once the file is over the directory where you ant to place the file, let go of the button and the file will be moved.