How to restart a server to regain access to it

I really have no idea how all of this works, and I keep having problems with being able to connect to one of my servers.

I have a MacBook Pro and a Shield Pro set up as servers. For some reason, I am almost never able to connect to my MacBook Pro server.

I was having connectivity issues with the MacBook Pro server, I clicked an option to remove the MacBook Pro server, and when I did that, it displayed the following message - “If this server is restarted, it will automatically be added to your account again.”.

Now I am trying to restart the server, which I THINK is done by opening Plex Media Server from the Launchpad, but it just opens Safari and tries to access http://127.0.0.1:32400/web/index.html. The page is never loaded, and I get a message of “Safari can’t connect to the server. Safari can’t open the page “127.0.0.1:32400/web/index/html” because Safari can’t connect to the server 127.0.0.1”.

Do any of you know what I’m supposed to do to regain access to that server?

Rebooting the laptop will also restart the server - that’s always an option.