How to Save a Document the First Time in Word 2013
Type a name for your document in the File Name box.
Word automatically selects the first line or first several words of your document as a filename and puts it in the Save As dialog box. If that’s okay, you can move to Step 5. Otherwise, type a name in the File Name box.
Be descriptive! The more concisely you name your document, the easier it is to recognize it by that name in the future.