Firefox allows you to add exceptions for sites with invalid certificates under certain circumstances. Are you getting the style of error page that has an "Advanced" button? If so, please click that button and copy/paste the more detailed error text/code in that section of the page into a reply.

I don't get anything specific, it's my firewall admin. I'm generating a new cert from an authority to resolve. It just gets frustrating when you get this big brother garbage without a way to turn off the incessant messages.

If the certificates work in IE, Edge, or Chrome, you should be able to export from there and import it into Firefox. However, without knowing the reason for the rejection, it's difficult to recommend whether to import the current "site" certificate (as a Server certificate) or the issuing certificate (as an Authority certificate). It sounds as though you might have a more convenient workaround already...

I think the larger issue is not where and how I obtain the certificates. It's the fact that I'm being impeded from making my own decisions on my network. I don't need a mommy or daddy helping me. I've been emancipated for years now and like be free to make my own choices.

Sorry, that is how Firefox works. You can request changes to future versions of Firefox here:

https://input.mozilla.org/feedback/firefox