Sometimes you might want to store general information about your file. To do this, go to File › Properties › Description. In the same menu under the tab Statistics you will get a summary of number of paragraphs, words, characters and so on your text contains.
A more succinct summary can be accessed directly under the menu Tools › Word Count. If you want the same information for just one particular section, mark it beforehand.
The name of the current editor is entered in another menu: Tools › Options › User data. This makes sense since the same document might well be edited by various people in succession – see section 18 on Proofreading.