Using CSS and templates for generated PDF from View

I've created a view from some Webform submissions that I need to make available to download/print as a PDF. I've explored Print, Email and PDF versions which I can't seem to get to work whatsoever. I decided to try Views PDF. I am able to get a PDF generated and look *somewhat* functional by playing around with the PDF and table settings in Views. However, I would like the PDF to display table borders and the table headers on each page (it's a multi-page PDF).

I'm new to Drupal and not exactly a code guru either to put it lightly. I understand that I can probably upload a CSS file and see if that will work to create borders and perhaps to duplicate headers but I'm not sure if that file needs to be where the other site CSS files are or if I can host it externally. One major problem that I don't have a whole lot of access to the back end of the site. I work for a University where I have to send modules, files, etc. through them and request deployment so that I can then utilize items through the admin interface of the site. So much of the help documentation doesn't exactly apply to my situation.

As an aside, I also get a "Technical issues" error whenever I try to upload a PDF template. I'm then unable to load the View PDF page. If I get rid of the template, it goes back to normal.

I've attached three different images to show the generated PDF, my settings page in Views and the error message I get when I try to add a template.