There are various walks and daytrips one can take. There seems to be plenty of skiing nearby (I was there in the fall).
One can walk 7 km or take a bus to Gosausee, a lovely lake which has a path all the way around it, or a bus to Hallstatt, a lovely touristy town. The town of Gosau is quiet but very pleasant, quite beautiful, no lake right there but stunning views of the Alps. A good quiet place to go if you prefer that to nightlife and tourists!