Cannot Open PDF in Safari

Can someone please help.

I cannot open PDF files through Safari. I've read some of the other comments on the same/similar issue and I have tried those steps and have been unsuccessful. I still cannot view PDF files through Safari, in fact, the Preview doesn't even open. When it worked the preview icon would pop up in the tool bar at the bottom of my Mac Book, but it no longer does that. Here is what I've tried;

Upgrading my Adobe, even though I know you don't need it for Mac.

Removed Adobe from applications and deleted.

Went to Library and internet plug ins and there is nothing in that folder.

Went to internet preferences and un clicked enable plug ins.

Not quite sure what else to do. Any help would be greatly appreciated. Thank you in advanced.