map folder

As of today I am new to this forum. Also installed Syncthing today on a Linux (ubuntu) and on an Odroid Hc1. Now I have linked the 2 machines. This works. But the problem is with me adding the correct folder. On the Odroid there is a folder /config/f2vab-tafsf On the Linux there is a directory /var/syncthing/f2vab-tafsf I think that’s good because I see updated. I don’t see these folders anywhere. I also tried to create a folder myself, but I get an error message. Can someone explain this