Most scanner software will scan directly to a .pdf
If yours does not, you will need a .pdf creator.
If you have Microsoft Office, you can download the free pdf maker they offer, scan the file as a .jpg, paste the .jpg into a Word document, then save the document as a .pdf.
If you do not have Office, you'll need to download a free .pdf maker such as you can get from
www.pdf995.com
Scan the file then print is as a .pdf document.
You can also download a free trial of Adobe Acrobat Professional which will work for 30 days and will create a .pdf file from the document you scanned. That can be time consuming if you only have 1 document though.
If all else fails, email me your scan and I can make it a .pdf Monday morning and email it back to you. I have Acrobat Pro at work.