Are there any services after a fresh ubuntu install, that are probably by most of the standard users not needed, so that you could recommend to disable them?
This is highly subjective depending on each user. Most services that start up with the standard
Some examples: If you don't use Evolution or, in particular, Evolution Calendars you can disable the Evolution Alarm Notify task. If you do not connect to this machine via VNC or another Remote Desktop tool you can disable the Remote Desktop server application. If your machine doesn't support Bluetooth you can also remove that service. Any service that you know you don't utilize while logged in as your user you can feel free to uncheck.