is a custom folder possible

I have just changed from Twonkey media server on my QNAP NAS to Plex, previously I had a custom folder called documentaries, this does not showup in Plex, I also have my movies in folders by actors names, this folder shows up dark grey in plex with a random shot from one of the movies as wall paper, can anyone help please?

Your best bet is to organize and name your media the way Plex needs it.

https://support.plex.tv/hc/en-us/categories/200028098-Media-Preparation