Purely out of curiosity: why isn't metadata available? Is it that you aren't naming/organizing your libraries correctly, or is it that you are consuming obscure media that isn't cataloged on any of the sites that power Plex's metadata functionality?
Either way, you could either:
a. Take the time to organize your library, like anyone who successfully uses Plex has.
or
b. Provide metadata to the open databases that Plex uses, to help both yourself and the next person who needs it.
The important thing to remember is that Plex is not made by wizards... it's software, and for it to catalog your library you need to name your files in a way that it can comprehend.