I want help to
- make Ubuntu 'update && upgrade' itself automatically,
- select the settings for this automatic system.
How can I do it? Please advice about
- where to find the menu (GUI) or file (command line) to do it,
- what settings that can be recommended (if different from the default).
As a bonus, please describe how different types of program packages are treated,
- program packages from Ubuntu repositories and PPAs
- snap packages
- flatpak packages
- other kinds of programs/packages.