Re: Set global preferences
Per-user preferences are stored in a user's home directory, in so-called "dot files", which are files and directories preceded by a '.' character. These files are not usually shown in file managers, so press Ctrl+H in Ubuntu's default file manager to see them, and again to hide them.
"Global preferences" are files stored in /etc/skel/ which are copied to a new user's home directory when the user is created. Put files in /etc/skel/ (as root) to set "Global preferences".
Unfortunately there isn't really a standard place where user settings are stored, especially for applications. However, I believe most settings are stored as a dconf database file in <home>/.config/dconf/user. It might also be worth checking (and editing) what is in /etc/skel/ by default.
I can go over any of these points if you have problems, although I don't actually have access to an Ubuntu machine at the moment.