I saved a file under templates that was downloaded from the web.

I cant open it, but i assume thats because im not in the correct program for that, its a pdf file btw, but thats not my question. I have two questions, 1. what do i need to open pdfs and put text in them? 2. how can i delete this download form my templates if i can not access it, its not highlighted and just grayed out? Im still new to mac os, so im still learning the ins and outs of it.