Why do you want to now change to a non-admin account?
The easiest option is to create a new User account with Admin Privs, log into it, and remove the Admin Privs from the original account.
Not sure what you need a duplicate of all the various folders, you'll only need an account name and password to enable the action being requested.
If you do want a duplicate - then simply create the new User account, and drag/drop the folders in the Admin account onto it.
Log out then into the new User account, and run Repair Permissions in Disk Utility (Apps>Utilities)
That'll be you ready to go.