1. Create or open your word document.
2. Now goto file Save as or press on F12 key. (F12 is the short cut key for save as on word)
3. Now select the place you want to save your document and give a file name.
4. Now select the file type as PDF and click on Save button.
Thats all now your file has been convert to pdf. It is better to save this file as word document too. Because some time you may need to edit it. PDF file difficult to edit.