@Stijn van der Schoor: Could anyone tell me where to find good Carbon tutorials for beginners. General tips or advice on how to start are also very welcome.

Your best bet is probably Learning Carbon by O'Reilly. You could also look at the CarbonDev site.

Also, keep in mind that the Carbon UI is now technically deprecated. It probably doesn't make sense to invest a lot of time in it now unless there's a specific reason you need it.