I know this must be a stupid qiestion but I have Adobe reader installed on my computer and can open PDF's but I cannot save a word document to PDF . Do I need more than adobe reader?
Yes, Adobe Acrobat, or some other third-party software. Adobe Reader is only capable of reading PDF files, not creating them or converting them to other formats.
You will have to use Adobe Acrobat or you can even use subscription based utility on Acrobat.com: https://www.acrobat.com/createpdf/en_GB/home.html