Getting a new guitar tomorrow excited to say the least. It's shipped here from germany (I live in Sweden) and I wonder what I need to do before I start playing the guitar?

advice needed!
The only reason to not do anything, is if the guitar has a nitro finish and it's been in a cold environment and has been brought into a warm environment. If that's the case, then let it sit for several hours in the box to slowly come up to room temperature. This prevents cold checking. Cold checking happens when a guitar with a nitro finish rapidly goes from warm to cold, or vice versa. The finish will actually crack. Look at some of the older, vintage guitars for examples of this.

If the finish is poly, which most newer guitars are, then open it up, tune up and play.
In addition to just letting the temperature differential settle, it might take a week or so before the wood adjusts to any great difference in ambient humidity.
Germany is a pretty temperate climate, and shouldn't be markedly different from Sweden.
However, if you use a lot of dry heat in the home, you might want to keep an eye on the humidity