Hello everyone.
I am completely new to both Linux and Plex. I bought my Pi out of curiosity and decided my first task would be to create a Plex Media Server I can use. And how I’ve failed. 
I am running Rasbian on a Raspberry Pi 3+ headlessly through both terminal and VNC on my Macbook Pro. I have also installed ExpressVpn on it, installed Netatalk to transfer files between the Pi and my Macbook and both are working just fine.
I followed this tutorial on youtube step by step for setting up my plex media server and everything went great until he enters: “sudo nano /etc/default/plexmediaserver”. My file was empty/non-existent, so I connected through my VNC to check the directory and found that the file I was looking for was called plexmediaserver.prev. I found that the file content was the same as in the video and continued the tutorial.
The problem occurs when I, through VNC, in the browser on the Pi type in: http://localhost:32400/web or https://localhost:32400/web or http://192.168.0.24:32400/web or http://192.168.0.27:32400/web or http://10.89.0.26:32400/web. I get a standard error page stating the site can’t connect and it is asking me to check my internet connection, firewall, and proxy settings. When I type the command Hostname -I i get those 3 local IPs.
I have been browsing the web for a little while now and I can’t seem to find an answer (or I simply don’t understand it?) so I was hoping someone in here might be able to help me out.
Thanks heaps in advance from an absolute Rookie.
Please undo any permission changes or simply just purge your current Plex package and start from scratch: 
Just really happy and grateful for the fast reply and explanation! Thanks heaps Uglymagoo! I’ll give it a try later tonight!