Hello Torun in Poland I presume. You may find the Answer in Virtual tourists very own travel guide to Poland on this very site :)
As far as I know there isn't any tourist bus taking tourists around the city. The best way to visit the attractions of Torun is on foot. The highlights are within the Old Town and the city is compact. It will take you about two hours to visit the most important places. So if you are going to stay out of the centre of the city, it is convenient to take a local bus (or taxi) to the Old Town and continue sightseeing on foot.
As pointed out, all the sights can easily be done on foot, try some of the cellar wine / beer places , loved Torun. Catch the local buses to visit nearby towns.