I would like to take an existing directory of my computer like photos and Via Syncthing have it to synchronize with many remote devices Creating directorys as required.
This is essentially what Syncthing is for. Just add an existing folder and share it with your connected devices, and then accept it on the other side. You can also use a little more advanced options like “auto accept” to make the process more automatic.
Before all, please check https://docs.syncthing.net/intro/getting-started.html if you haven’t yet.
On the remote sides, from within Syncthing when accepting the new Folder, carefully define the path were ST will create the directory.