Try PDF Standalone,

It's free & online, and also the safest because only works on your browser without uploading your data.

I havent personally used this, but it has been recommended to me.

PDF (Portable Document Format) is a file format for general preview of the finished jobs. It is not a Post Script file format intended for print (although high quality PDF files may be suitable for print). Generally, while creating a PDF file the images are down sampled or compressed using image compression technologies. Also, the whole file is compressed with other available compression technologies. These compression reduce the file size of the document while compromising with the quality, thus making the document not suitable for high-end printing.

www.google.co.in sub kuch milata hai please find it

You can add a PDF to your Facebook (or other social media) posts by first publishing the PDF online and then posting a link to the PDF. The easiest way to post the PDF online is to use a cloud storage provder like Google Drive or Dropbox and then share the file using a share link.

If you want to track the file and know how many times it's been downloaded or viewed check out a document tracking tool like www.orangedox.com