May I travel to other Schengen-States with my Schengen-Visa?
Yes. That is the purpose of the Schengen-Visa. You can, for example, fly to Amsterdam and enter the Netherlands with a German Schengen-Visa, so that you can then visit friends in Oldenburg, Germany, by train. You can, of course, also travel to Munich, Germany, with a Schengen-Visa for Austria, and then travel on to Austria, as long as Austria is your main travel destination.