There are various ways to do that:
1- If you have Adobe Acrobat installed on the computer, you can click ACROBAT tab>Create PDF to create pdf from Word.
Or use File>Save as Adobe PDF in MS Word.
2-If you have subscribed to Adobe PDF Pack, you can download Reader and click on Create PDF option under Tools to convert files to PDF.
3-You can also save a Word document as a pdf in MS Word by clicking File>Save As>chooose Save as type>PDF (*.pdf)>Save
4-To save Google doc as a pdf, open the pdf file in Google Docs>click File in the top left corner>Download as>PDF Document
Let me know if you have further questions.