I have been trying to set up a icon for my server. I have looked at countless YouTube videos and None of them helped at all. If you could help me that would be awesome! 
I looked at this plugin, ServerListPlus which supposedly adds server icons (Favicons), But that plugin doesn’t work for me. 
In your server directory, place a 64x64 PNG file named server-icon.png, then restart your server. Yep, that’s it.
I tried I’m Pretty sure it was 64x64…
it must be an actual PNG filetype as well, not a jpg called png, or a file that gets saved as server-icon.png.png …
open the image in paint or open image editor and look at the picture dimensions just to be sure.
Also make sure did enable viewing file extensions so server-icon.png.png doesnt get created when saving
I remember when I did mine there was an issue about it needing to be 8bit png? Or maybe it was the other way around and it needed to be 24bit. Have you tried messing with that?
OK, i’ve got it… For all the users working in GIMP, you have to export once or twice as a .png file then save it directly to you server’s folder.