Difficulty in handling the server.

How do I find out where users’ files are saved and how do I change them? Use ubuntu server.

Seafile uses its own data model. Maybe you might take a look at: https://manual.seafile.com/develop/data_model.html to see how it works. Single files can be accessed via web interface, webdav or seafile drive client.

You can acces them in the preferences if you enabled admin user repo view or with SeaFuse.