For this you need to tell the server to create the file and reference map-settings and map-gen-settings. Not sure which walk through you looked up, but I found the wiki explains this quite well: https://wiki.factorio.com/Multiplayer#Dedicated.2FHeadless_server.


The other walkthrough didn't have ...

Followed a walk through, was mentioned to put that in there to name the save/always load latest... how should that line be phrased?
I have not looked at server setups for a long time so I might be wrong but I would expect either:
--start-server ./saves/SaveFileName.zip
or
--start-server-load ...

info.json is a file inside the .zip save file. Either the latest save is corrupted or you have a zip file in the folder that is not an actual factorio save file.

Edit:
Not sure, but
--start-server-load-latest /opt/factorio/saves/3rd.zip
does not make sense to me, either you want the latest save ...

I found the file in multiple locations (not zipped) however I'm not sure where it's supposed to be, or what file references it.


Also, this is a fresh vanilla server, first time trying to run it.

Everytime I try to launch my headless server (ubuntu) with the following commands, I get the error "Error ServerMultiplayerManager.cpp:94: MultiplayerManager failed: "File /info.json not found""...

systemctl daemon-reload
systemctl start factorio

After running "systemctl status factorio.service ...