I need help with nas connection

I have 4 nas devices on my network. I am wanting to add movies from only 1 nas device folder. I am able to select select the 1 nas I want to create the library from but I am not sure if the library will just be the movies from it. I am very new to Plex and I really have a lot of questions about it. Any help would be greatly appreciated.

Lots of Support Articles you can read to get you started.

So first thing. Movies need to be in a Movies library, tv shows in a TV Shows library. You can’t mix and match them. Each library type uses a different scanning agent to identify the movie or tv shows and get the proper metadata.

If you point Plex at a single folder for a library, it shouldn’t reach outside that folder looking for new material.