Can't help with the play date, but you might consider joining a Welpenspielstunde, a puppy play group - this is the first step in socialization, and very much recommended in Switzerland. To find a group/trainer in your area, there is a database maintained by the BVEt:
http://bvet.bytix.com/plus/trainer/
Putting in Goldach leads to many hits; you'd need to look at each to see who offers Welpenspielestunde.
Attending a Welpenspielstunde is a very good way to get to know other dog owners in your area, and to start your puplet out on the right road.
(And don't forget the SKN, the obligatory training course - you have 12 months to do this.

)
All the best with your little one. (Who is seriously cute, by the way.

)